EK MCAT Biology

The following statement is true concerning the product of vectors, if the product is a _______? The vector product will point in a direction perpendicular to both original vectors, and have a magnitude proportional to the sine of the angle between both original vectors.

vector

How are the hydrolytic enzymes of a lysosome activated?

via a low pH which is achieved by pumping protons into the interior of the lysosome.

How are nucleotides joined together?

via phosphodiester bonds between the phosphate group of one nucleotide and the 3rd carbon of the pentose of the other nucleotide forming long strands.

A virus following a lytic cycle is called a ?

virulent virus which precipitates symptoms in the host

A _____ cannot contain both RNA and DNA at the same time.

virus/virion

Terpenes:

vitamin A for vision.

Though the spinal cord acts mainly as a conduit for nerves to reach the brain, it does possess limited integrating functions such as :

walking reflexes, leg stiffening, and limb withdrawing from pain reflexes, known as reflex arcs.

What do osteoclasts develop from?

white blood cells called monocytes

Any two masses undergoing free fall near Earth's surface will have the identical _______ due to __________ and therefore hit the ground at the ______ time, assuming they were dropped at the same time and there is no air resistance.

will have the identical acceleration due to gravity and therefore hit the ground at the same time.

Is cardiac muscle striated?

yes

Is skeletal muscle striated?

yes

Except for the _____, all cells of Zygomycota are ______.

zygospore; haploid

______ is an anterior pituitary tropic peptide hormone that stimulates the adrenal cortex to synthesize and release glucocorticoids via the second messenger system using cAMP.

Adrenocorticotropic Hormones (ACTH)

How does adult skeletal muscle create new muscle cells if at all?

Adult skeletal muscle does not undergo mitosis to create new muscle cells (hyperplasia). - instead, a number of changes occur over time as the muscles are exposed to forceful, repetitive contractions - these changes include: the diameter of the muscle fibres increase, the number of sarcomeres and mitochondria increase, and sarcomeres lengthen. - Muscle cells are so specialized that they have lost the ability to undergo mitosis. Only in rare cases does one muscle cell split to form 2.

What does the embryo become after 8 weeks of gestation?

After 8 weeks of gestation, the embryo becomes a fetus and receives oxygen and nutrients directly from its mother through a specialized circulatory system consisting of the placenta and the umbilical cord.

________, a steroid, is a mineral corticoid that acts in the distal convoluted tubule and the collecting duct to increase Na⁺ and Cl⁻ reabsorption and K⁺ and H⁺ secretion. Essentially, this hormone regulates plasma levels of electrolytes and consequently, total extracellular water volume.

Aldosterone: - Increases reabsorption of Na⁺ and Cl⁻ into blood - Increases Secretion of H⁺ and K⁺ in urine - thus, due to aldosterone creating a net gain of electrolytes in the blood plasma, osmosis will pull more water into the blood and increases blood volume and blood pressure

What could Hyperventilation cause?

Alkalosis by increasing the blood pH too far

Where do all blood cells differentiate from?

All blood cells differentiate from the same type of precursor, a stem cell residing in the bone marrow.

What is the path of the blood received by the liver?

All blood received by the liver moves through large flattened spaces called the hepatic sinusoids and collects in the hepatic vein, which leads to the inferior vena cava... then to the heart to be reoxygenated and pumped through the body.

What happens to the remaining solute found in the filtrate of the nephron once the proximal transport proteins have reached transport maximum?

All further solute in the filtrate will be washed into urine.

How do all hormones act?

All hormones act by binding to proteins called receptors. - each receptor is highly specific for its hormone - one method of hormone regulation occurs by the reduction or increase of these receptors in the presence of high or low concentrations of the hormone - some hormones have receptors on virtually all cells, while other hormones have receptors only on specific tissues - very low concentrations of hormones in the blood have significant effects on the body.

Where are all peptide hormones manufactured?

All peptide hormones are manufactured in the Rough ER, typically as s preprohormone that is larger than the active hormone. The preprohormone is cleaved in the ER lumen to become a prohormone, and is then transported to the golgi. - In the golgi, the prohormone is cleaved and modified with carbohydrates to its final active form. - the golgi then packages the hormone into secretory vesicles, and, upon stimulation by another hormone or a nervous signal, the cell releases the vesicle via exocytosis.

Where do the steroid hormones come from?

All steroid hormones come from the adrenal cortex, gonads or the placenta. Testosterone is also produced in the adrenal cortex

What stage of development are all the female eggs arrested at?

All the eggs of the female are arrested as primary oocyte at birth.

____ are the different versions of a specific gene

Alleles

Alleles are referred to as ____ or ____ dominant when a heterozygous individual exhibits a phenotype that is intermediate between its homozygous counterparts.

Alleles are referred to as partially or incompletely dominant when a heterozygous individual exhibits a phenotype that is intermediate between its homozygous counterparts.

How do Allosteric interactions regulate enzyme activity?

Allosteric regulation is the modification of the enzyme configuration resulting from the binding of an activator or inhibitor at a specific binding site on the enzyme.

Describe single unit smooth muscle:

Also called visceral, is the most common. - single unit smooth muscle cells are connected by gap junction spreading the action potential from a single neuron through a large group of cells, and allowing the cells to contract as a single unit. - single-unit smooth muscle is found in the arteries and veins, the stomach, intestines, uterus, and urinary bladder. - Basically, numerous muscle fibres are innervated by a single autonomic neuron, and so all muscle fibres innervated by the single neuron fire at the same time

What is the phenotypic ratio of a monohybrid cross?

Also known as the Mendelian Ratio is 3:1.

ADH is ___ ___ ___ in the collecting duct.

Always digging holes

How do amino acids contribute to energy production?

Amino acids are deaminated in the liver and the deaminated product is either chemically converted to pyruvic acid or acetyl CoA, or it may enter the Krebs cycle at various stages depending on which amino acid was deaminated.

What happens when cells reach their upper limit for protein storage?

Amino acids can be burned for energy or converted to fat for storage.

Where do the amino acids go from the enterocytes?

Amino acids undergo facilitated diffusion to the basolateral side of the small intestine where they are absorbed into the portal vein and transported to the liver, they are quickly taken up by all cells of the body, especially the liver.

What is the A Band of a sarcomere?

An A-band contains the entire length of a single thick filament (myosin). - this is the region between two Z bands

What is the entire system of Haversian canals and lamellae called?

An Osteon or Haversian System: - The osteon or Haversian system is the fundamental functional unit of compact bone. Osteons are roughly cylindrical structures that are typically several millimeters long and around 0.2mm in diameter. - Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surround a central canal, the Haversian canal. The Haversian canal contains the bone's nerve and blood supplies. The boundary of an osteon is the cement line. Between adjoining osteons there are angular intervals that are occupied by interstitial lamellae. These lamellae are remnants of osteons the greater parts of which have been destroyed. Near the surface of the compact bone the lamellae are arranged parallel to the surface; these are called circumferential lamellae. Some of the osteoblasts develop into osteocytes, each living within its own small space, or lacuna. Osteocytes make contact with the cytoplasmic processes of their counterparts via a network of small transverse canals, or canaliculi. This network facilitates the exchange of nutrients and metabolic waste. Collagen fibers in a particular lamella run parallel to each other but the orientation of collagen fibers within other lamellae is oblique. The collagen fiber density is lowest at the seams between lamellae, accounting for the distinctive microscopic appearance of a transverse section of osteons. The space between osteons is occupied by interstitial lamellae, which are the remnants of osteons that were partially resorbed during the process of bone remodelling. Osteons are connected to each other and the periosteum by oblique channels called Volkmann's canals or perforating canals.

What does all muscle contraction begin with?

An action potential which then releases acetylcholine into the synaptic cleft. - acetylcholine then activates ion channels of the motor end plate located on the sarcolemma. - this initiates a new action potential inside the muscle fibre. - this new AP moves deep into the muscle fibre via T-tubules - The AP is eventually transferred to the sarcoplasmic reticulum, which then becomes permeable to Ca²⁺ ions. - then contraction of the sarcomere units occurs - at the end of the cycle, Ca²⁺ is actively pumped back into the sarcoplasmic reticulum⁺

Describe Autosomal Recessive Inheritance:

- alleles found on autosomal chromosomes 1-22 - occurs when an allele of one of the chromosomes does not express the trait/disease unless another copy of the recessive gene is present on the homologous chromosome. - affected people are born to unaffected people or asymptomatic parents. - equally transmitted by either sex - child of a carrier(Aa) x carrier (Aa) has a 25% chance of being affected and 50% of being a carrier - child of a carrier(Aa) x affected (aa) has a 50% chance of being affected and 50% chance of being a carrier - child of a carrier (Aa) x unaffected (AA) has a 50% chance of being a carrier (Aa) - child of affected (aa) x unaffected (AA) has 100% of being a carrier - child of affected (aa) x affected (aa) has a 100% chance of being affected - example is cystic fibrosis

Carbohydrates:

- also called sugars or saccharides, are made from carbon and water. They have the empirical formula C(H₂O). - Five and six carbon carbohydrates (pentoses and hexoses) are the most common in nature.

Describe the Oxygen Dissociation Curve:

- as O₂ pressure increases, the O₂ saturation of Hb increases sigmoidally (S-shape). - this curve of Oxyhemoglobin (HbO₂), shows the percent of hemoglobin that is bound with oxygen at various partial pressures of oxygen. - in the arteries of a normal person breathing room air, the oxygen saturation is 97%

Describe Glucose:

- exists heavily in the ring form over the chain form. - The ring form has two anomers: α and β glucose

What is the structure of the Kidney?

- outer cortex - inner medulla - Urine created in kidney is emptied into renal pelvis - Renal pelvis is emptied by ureter - Ureter carries urine to bladder - Bladder drained by the urethra

Describe Platelets and their role in the body:

- platelets are also known as thrombocytes - Platelets are involved in injury repair - they are derived from small portions of membrane-bound cytoplasm torn from megakaryocytes. - megakaryocytesis a bone marrow cell responsible for the production of blood thrombocytes (platelets), which are necessary for normal blood clotting. - no nucleus containing DNA - Platelets are a natural source of growth factors. They circulate in the blood of mammals and are involved in hemostasis, leading to the formation of blood clots. - Platelets are a natural source of growth factors. They circulate in the blood of mammals and are involved in hemostasis, leading to the formation of blood clots. - they contain actin and myosin, residuals of the golgi and the ER, mitochondria, and are capable of making prostaglandins and some important enzymes

Proteins:

- proteins are built from a chain of amino acids linked together by peptide bonds - proteins may be called polypeptides. - nearly all proteins in all species are built from the same 20 alpha-amino acids.

What are the enzymes released into the duodenum from the pancreas?

- trypsin - chymotrypsin - pancreatic amylase - lipase - ribonuclease - deoxyribonuclease *** all these enzymes are released as zymogens and thus must be activated within the small intestine.

Describe Lysogenic infection:

- viral DNA is incorporated into host genome, or, if the virus is an RNA virus, it possesses the enzyme reverse transcriptase, DNA is actually reverse-transcribed from the RNA and then incorporated into the host cell's genome. - The viral DNA is then replicated with the host cell DNA each time replication ensues - a virus in the lysogenic life cycle is called a temperate virus, with no symptoms in the host cell or organism. - The viral DNA remains incorporated in the host cell genome, the virus is dormant or latent, and is called a provirus or prophage (if the host cell is a bacterium).

Describe Lytic Infection:

- virus takes over cell's reproductive machinery and starts producing new viruses. - The brief period before the first fully formed virion appears is called the eclipse period. - The cell may fill with new viruses until it lyses of bursts, or it may release the new viruses one at a time in a reverse endocytotic process.

What is the resting potential of most neurons?

-70mV on the inside of the membrane/cell and more positive outside the cell.

Describe the location and function of the Chief/peptic cells of the stomach:

...

Sickle cell anemia is an autosomal recessive disease. A male with the disease, and a female that is not diseased, but carries the trait, produce twi girls. What is the probability of that neither girl carries a recessive allele?

0 % because each girl will receive the recessive trait from the father.

At 0°, Fnet=mgsinθ=?

0, no slide down a slope.

How many ATP are produced from one turn of the krebs cycle?

1

How many FADH₂ are produced from one turn of krebs cycle?

1

How many spermatozoa does one spermatogonium produce?

1 spermatogonium produces 8 spermatozoa

What are phospholipids composed of?

1) A polar phosphate group as the head 2) 2 fatty acid chains that are non-polar 3) glycerol backbone

What are the 2 forms of starch?

1) Amylose: an isomer of cellulose that may be branched or unbranched and has the same alpha linkages as glycogen. 2) Amylopectin: resembles glycogen but has a different branching structure.

What are the main shapes of Bacteria?

1) Cocci= round 2) Bacilli= rod shaped 3) Spirilla= helically shaped if they are rigid; and 4) Spirochetes= if the helically shaped are not rigid

What are the 5 forces that create the 3° structure?

1) Covalent disulfide bonds between two cysteine amino acids on different parts of the chain 2) Electrostatic (ionic) interactions, mostly between acidic and basic chains. 3) Hydrogen bonds 4) van der waals 5) Hydrophobic side chains push away from water (toward center of protein)

What are the 2 possible plasmids mentioned on the MCAT?

1) F plasmid or fertility factor/F Factor: conjugative plasmid - a bacterium with the F plasmid is called F+, while the other without the F plasmid is called F-. 2) R plasmid: is also a conjugative plasmid - donates resistance to certain antibiotics

What are the 2 main types of proteins?

1) Globular: globular proteins function as enzymes (pepsin), hormones (insulin), membrane pumps and channels (Na+/K+ pump and voltage gated sodium channels), membrane receptors (nicotinic receptors on post-synaptic neuron), intercellular and intracellular transport and storage (Hb and Mb), osmotic regulators (albumin), in the immune response (antibodies), etc. 2) Structural: made from long polymers. They maintain and add strength to cellular and matrix structure. Collagen, is most abundant protein in body. Microtubules, which make up eukaryotic flagella and cilia, are made from globular tubulin, which polymerizes under the right conditions to become a structural protein.

What are the structural components of a virus?

1) Head= protein coat called a capsid, holding one to several hundred genes in the form of RNA or DNA. 2) Contain a lipid-rich envelope either borrowed from the host membrane or synthesized in the host cell cytoplasm 3) Tail 4) Tail fibre used to attach virus to surface of a bacterium 5) Viruses have NO organelles or nucleus

What are the 3 mechanisms by which we classify enzyme inhibitors?

1) Irreversible 2) Competitive 3) Non-competitive

What are Newton's 3 Laws?

1) Law of Inertia: an object in a state of rest or in a state of motion will tend to remain in that state unless it is acted upon by a net force. 2) When an object is acted upon by a net force, the change in that object's state of motion will be inversely proportional to the mass (m) of the object and directly proportional to the net force (F) acting upon the object. F=ma 3) For every action there is an equal and opposite reaction. When object A applies a force to object B, object A experiences a force of equal magnitude but in the opposite direction.

What are the two theories of enzyme specificity?

1) Lock and key Model 2) Induced Fit

What are the 2 possible paths for the viral genetic material once inside the cell?

1) Lysogenic Infection 2) Lytic Infection

What are the 3 steps of metabolism?

1) Macomolecules (polysaccharides, proteins and lipids) are broken down into their constituent parts (monosaccharides, amino acids, and fatty acids) releasing little or no energy. 2) Constituent parts are oxidized to acetylCoA, pyruvate or other metabolites forming some ATP and reduced coenzymes (NADH and FADH₂) in a process that does not directly utilize oxygen. 3) If oxygen is available and the cell is capable of using oxygen, these metabolites go into the Citric Acid Cycle and oxidative phosphorylation to form large amounts of energy (NADH and FADH₂, or ATP); otherwise the coenzyme NAD+ and other byproducts are either recycled or expelled as waste.

What are the 5 types of Sensory Receptors?

1) Mechanoreceptors for touch 2) Thermoreceptors for temp change 3) Nocireceptors for pain 4) Electromagnetic receptors for light 5) Chemoreceptors for taste, smell and blood chemistry

What are the 5 main steps involved in the AP?

1) Membrane is at rest, sodium and potassium channels are closed, Na⁺/K⁺ pump is at work to maintain resting potential. 2) Sodium channels open, allowing sodium to flow into the cell, causes the inside of the cell to be more positive, called depolarization. 3) Potassium channels open as sodium channels begin to inactivate. This allows the potassium out of the cell, causing the cell to repolarize. 4) Since the potassium channels are slower to respond than sodium channels, this leads to hyperpolarization, where the inside of the membrane is more negative than normal, to - 70mV. 5) Potassium channels close and the membrane equilibrates to its resting potential of -50mV

What do minerals do in the body?

1) electrochemical gradient 2) combine and solidify to give strength to a matrix, such as hydroxyapatite in bone. 3) Act as cofactors assisting enzyme or protein function. Ex) Iron is a mineral found in heme, the prosthetic group of cytochromes.

What are the 4 basic types of tissues in animals?

1) epithelial 2) muscle 3) connective 4) nervous

What 3 classes of molecules make up animal cell matrices?

1) glycosaminoglycans and proteoglycans, 90% 2) structural proteins 3) adhesive proteins

All organisms acquire energy from one of two sources:

1) light; or 2) oxidation of organic or inorganic matter

Contact forces must act in at least one of two directions:

1) perpendicular to a surface (Force normal) and/or, 2) parallel to a surface (Friction) An exception is tension, which is a contact force that can act in any direction away from the object.

Any object that contacts your system may apply forces in which two directions?

1) the normal force is always perpendicular to the contact surface 2) a frictional force is always parallel to the contact surface

What are the 3 types of junctions that connect animal cells?

1) tight 2) desmosomes 3) Gap

What are the 2 anomers of glucose?

1) α-Glucose: the hydroxyl group on the anomeric carbon (carbon number 1) and the methoxy group (on carbon 6) are on opposite sides of the carbon ring. 2) β-Glucose: The hydroxyl group and the methoxy group are on the same side of the carbon ring.

What are the 4 major cell types of the Epidermis?

1- 90% of the epidermis is composed of keritinocytes, which produces keratin, which helps waterproof the skin. 2- Melanocytes: transfer the melanin to keratinocytes 3- Langerhans cells interact with the helper T-cells of the immune system 4- Merkel cells attach to sensory neurons and function in the sensation of touch

Describe the process of skeletal muscle contractions:

1- An action potential originating in the CNS reaches an alpha motor neuron, which then transmits an action potential down its own axon. 2- The action potential propagates by activating voltage-gated sodium channels along the axon toward the neuromuscular junction. When it reaches the junction, it causes a calcium ion influx through voltage-gated calcium channels. 3- The Ca2+ influx causes vesicles containing the neurotransmitter acetylcholine to fuse with the plasma membrane, releasing acetylcholine out into the extracellular space between the motor neuron terminal and the neuromuscular junction of the skeletal muscle fiber. 4- The acetylcholine diffuses across the synapse and binds to and activates nicotinic acetylcholine receptors on the neuromuscular junction. Activation of the nicotinic receptor opens its intrinsic sodium/potassium channel, causing sodium to rush in and potassium to trickle out. Because the channel is more permeable to sodium, the charge difference between internal and external surfaces of the muscle fiber membrane becomes less negative, triggering an action potential. 5- The action potential spreads through the muscle fiber's network of T-tubules, depolarizing the inner portion of the muscle fiber. 6- The depolarization activates L-type voltage-dependent calcium channels (dihydropyridine receptors) in the T tubule membrane, which are in close proximity to calcium-release channels (ryanodine receptors) in the adjacent sarcoplasmic reticulum. 7- Activated voltage-gated calcium channels physically interact with calcium-release channels to activate them, causing the sarcoplasmic reticulum to release calcium. 8- The calcium binds to the troponin C present on the actin-containing thin filaments of the myofibrils. The troponin then allosterically modulates the tropomyosin. Under normal circumstances, the tropomyosin sterically obstructs binding sites for myosin on the thin filament; once calcium binds to the troponin C and causes an allosteric change in the troponin protein, troponin T allows tropomyosin to move, unblocking the binding sites. 9- Myosin (which has ADP and inorganic phosphate bound to its nucleotide binding pocket and is in a ready state) binds to the newly uncovered binding sites on the thin filament (binding to the thin filament is very tightly coupled to the release of inorganic phosphate). Myosin is now bound to actin in the strong binding state. The release of ADP and inorganic phosphate are tightly coupled to the power stroke (actin acts as a cofactor in the release of inorganic phosphate, expediting the release). This will pull the Z-bands towards each other, thus shortening the sarcomere and the I-band. 10- ATP binds to myosin, allowing it to release actin and be in the weak binding state (a lack of ATP makes this step impossible, resulting in the rigor state characteristic of rigor mortis). The myosin then hydrolyzes the ATP and uses the energy to move into the "cocked back" conformation. In general, evidence (predicted and in vivo) indicates that each skeletal muscle myosin head moves 10-12 nm each power stroke, however there is also evidence (in vitro) of variations (smaller and larger) that appear specific to the myosin isoform. 11- Steps 9 and 10 repeat as long as ATP is available and calcium is present on thin filament. 12- While the above steps are occurring, calcium is actively pumped back into the sarcoplasmic reticulum. When calcium is no longer present on the thin filament, the tropomyosin changes conformation back to its previous state so as to block the binding sites again. The myosin ceases binding to the thin filament, and the contractions cease. - The calcium ions leave the troponin molecule in order to maintain the calcium ion concentration in the sarcoplasm. The active pumping of calcium ions into the sarcoplasmic reticulum creates a deficiency in the fluid around the myofibrils. This causes the removal of calcium ions from the troponin. Thus, the tropomyosin-troponin complex again covers the binding sites on the actin filaments and contraction ceases.

What are the 5 Mendelian Pedigree patterns?

1- Autosomal Dominant inheritance 2- Autosomal recessive inheritance 3- X-linked recessive inheritance 4- X-linked dominant inheritance 5- Y-linked inheritance

What are the two causes of genetic drift?

1- Bottleneck Effect: a population contracts to a significantly smaller size over a short period of time due to a random environmental event (thereby leading to the loss of alleles from the population) 2- The Founder Effect: a small group of individuals leaves a larger population and establishes a new population. The new population's gene pool will reflect the alleles carried by the founders and may be different from the larger population.

What are the two hormones that determine the continual process of bone remodification via the osteoclasts and osteoblasts?

1- Calcitonin decreases osteoclast activity, thus decreases blood calcium levels by keeping more bone intact. 2- Parathyroid hormone increases osteoclast activity, thereby increasing blood calcium levels by increasing bone tissue breakdown.

What are the 6 major groups of lipids:

1- Fatty Acids 2- Triacylglycerols 3- Phospholipids 4- Glycolipids 5- Steroids 6- Terpenes

What are the 3 types of joints?

1- Fibrous Joints 2- Cartilaginous Joints 3- Synovial Joints

What are the types of isolation that may exist between different species?

1- Geographic isolation 2- habitat isolation 3- seasonal isolation 4- mechanical isolation 5- gametic isolation 6- developmental isolation 7- hybrid inviability or sterility 8- selective hybrid elimination 9- behavioural isolation

What are the 6 major hormones of the Anterior Pituitary?

1- Human growth hormone; HGH 2- Adrenocorticotropin (ACTH) 3- Thyroid stimulating hormone (TSH) 4- Follicle stimulating hormone (FSH) 5- Leutinizing hormone (LH) 6- Prolactin * All anterior pituitary hormones are peptide hormones

List and describe the 3 types of cartilage:

1- Hyaline: also called articular, is the most common. It is found in joints, on the ends of bones and it reduces friction and absorbs shock in joints 2- Fibrocartilage 3- Elastic

What are the 4 major functions of the catecholamines?

1- Increase conversion of glycogen to glucose in the liver (raising blood glucose levels) 2- Increase rate and strength of the heart beat 3- vasoconstrict blood vessels to internal organs 4- Vasodilate blood vessels of skeletal muscle

What are the 3 main inhibitions caused by progesterone and estrogen?

1- Inhibits GnRH from the hypothalamus, thus inhibiting the releases of LH from the ant.pit. 2- Inhibits GnRH from the hypothalamus, thus inhibiting the releases of FSH from the ant.pit. 3- Inhibits the release of prolactin from the anterior pituitary

What are the 3 specialized cells of the Epidermis?

1- Keratinocytes 2- Melanocytes 3- Dendritic cells that are phagocytes that eat pathogens and activate the immune response.

According to the Hardy-Weinberg Principle, there should be no change in the gene pool of a sexually reproducing population possessing which five conditions?

1- Large populations 2- Mutational Equilibrium 3- Immigration or emigration must not change the gene pool 4-random mating 5- no selection for the fittest organism

What are Mendel's two major laws of inheritance?

1- Law of Segregation 2- Law of Independent Assortment

What are the four types of bones?

1- Long 2- Short 3- Flat 4- Irregular

What are the 4 major cell types of the stomach?

1- Mucous cells 2- Chief (peptic) cells 3- Parietal (oxyntic) cells 4- G cells - all these cells are located within the gastric pits and glands of the stomach

What are the 3 divisions of the ear?

1- Outer ear 2- Middle ear: Tympanic membrane, Stapes, Malleus, Incus 3- Inner ear: Semicircular canal, oval window, cochlea, vestibulocochlear nerve, round window

What are the 3 basic chemistry types that hormones exist in?

1- Peptide hormones 2- Steroid hormones 3- Tyrosine derivatives

What are the two opposing reproductive strategies?

1- R-selection 2- K-selection

What are the 3 types of skeletal muscle fibres?

1- Slow oxidative (type I): Slow Twitch 2- Fast oxidative (type II A): Fast Twitch A 3- Fast glycolytic (type II B): Fast Twitch B

What are the 2 principal parts of the skin?

1- The Epidermis 2- The Dermis

Once bound by a peptide hormone, the membrane-bound receptor may act in which possible ways?

1- The receptor may act itself as an ion channel increasing membrane permeability to a specific ion 2- the receptor may activate or deactivate other intrinsic membrane proteins also acting as ion channels 3- Another effect may be to activate an intracellular second messenger such as cAMP, cGMP, or calmodulin. This second messenger activates or deactivates enzymes and/or ion channels and often creates a cascade if chemical reactions that amplifies the effect of the hormone.

What are the important functions of the skin?

1- Thermoregulation 2- Protection: produces melanin which protects against UV radiation. 3- Environmental Sensory Input 4- Excretion 5- Immunity 6- Blood reservoir 7- Vitamin D synthesis 8- Water Homeostasis

Describe the 5 stage cycle of a single myosin head acting with a single actin molecule/polymer:

1- Tropomyosin covers the active site on actin, which prevents the myosin head from binding to actin. During this time, the myosin head is in a high energy, cocked state as it possesses a phosphate and ADP group. 2- After a signal for muscle contraction, Ca²⁺ ions are released from the sarcoplasmic reticulum and bind to the troponin molecule, which causes tropomyosin to pull away from the active site of actin. This frees up the myosin binding site so that the myosin head can bind to actin.. forming the cross-bridge. 3- The myosin head releases phosphate and ADP and bends into a low energy position, thus dragging the actin filament along with it. The bending of the myosin filament is what causes the contraction. 4- ATP attaches to the myosin head, releasing it from the active site of actin (Ca²⁺ dissociates from troponin, allowing for tropomyosin to again cover the actin active site) 5- ATP hydrolyzes to ADP+Pi and the myosin head goes back to its cocked, high-energy position.

Describe the process of the Renin-Angiotensin System:

1- When blood volume/pressure decreases and is sensed by the kidney, juxtaglomerular and liver cells produce renin. 2- Renin converts the plasma protein angiotensinogen (produced in liver) to angiotensin 1 3- Angiotensin 1 is converted into angiotensin 2, by angiotensin converting enzyme (ACE). 4- Angiotensin 2 stimulates the adrenal cortex to secrete aldosterone. 5- Aldosterone increase Na⁺ and Cl⁻ reabsorption from the kidneys into the blood, leading to an increase in blood volume and pressure. This is regulated by a negative feedback mechanism.

What are the 4 primary taste sensations?

1- bitter 2- sour 3- salty 4- sweet

What are the types of exocrine glands?

1- sudoriferous (sweat) 2- sebaceous (oil) 3- mucous 4- digestive

How long after a meal does the chylomicron level in the blood peak?

1-2 hours - but it falls rapidly, as the fat digestates are absorbed into the cells of the body.

What are the 3 main uses for transported fatty acids?

1. storage in adipose tissue 2. oxidized for fuel is muscles 2. modified to provide structural support for plasma membranes.

What are the main functions of the Kidney?

1. to excrete waste products, such as urea, uric acid, ammonia, and phosphate 2. to maintain homeostasis of the body fluid volume and solute composition 3. to help control plasma pH

How many aa are essential in humans?

10 of the aa are essential in humans. The body cannot manufacture these 10, they must be directly ingested.

How old is the universe?

12 to 15 billion years old

What is a normal heartbeat for a healthy resting adult?

120mmHg systolic and 80mmHg diastolic

How many turns of the Krebs cycle does 1 glucose produce?

2 turns

What are the products of glycolysis from the breakdown of a single glucose molecule?

2 x pyruvate 2 x NADH 2 x ATP

How long does the primary immune response need in order to reach its full potential?

20 days

1 NADH = ___ ATP?

3

How many NADH are produced via 1 turn of the Krebs cycle?

3

How long is the small intestine?

3 m in length

What is the total ATP derived from 1 glucose molecule?

36

According to the monohybrid cross of a parent who is homozygous for the purple allele and a parent who is homozygous for the white allele, what would the phenotypic ratio be for the F₂ generation?

3:1 (purple:white) - This is the case is each original parent was homozygous for their specific allele.

How much energy can be created per gram or protein?

4 calories per gram of protein.

How much energy is created per gram of carbohydrate?

4.5 calories

What is oxygen pressure in body tissues, and what is the result?

40 mmHg. - thus, as blood moves through the systemic capillaries, oxygen diffuses to the tissues (from high to low pressure), and carbon dioxide diffuses to the blood.

Normally, __-__synapses must fire simultaneously on the same neuron in order for an EPSP to create an action potential within that neuron.

40-80

How many bacteria can a single neutrophil phagocytize?

5 to 20 bacteria

Veins, venules and venus sinuses in the systemic circulation contain __% of the blood by volume, while arteries, arterioles and arteries in the systemic circulation contain ___% of the blood by volume.

64%; 20%. - Thus the veins, venules and venus sinuses contain a far greater volume of blood than do arteries, arterioles and capillaries. - the veins, venules and venus sinuses act as a reservoir for blood.

What is the percent composition of healthy feces?

75% water Out of the remaining solid mass: - 30% is dead bacteria - 10-20% fat from bacteria and sloughed enterocytes - 10-20% inorganic matter - 2-3% protein - 30% roughage (cellulose) and undigested matter

What are the proportions of gases that exist in the air we breathe out?

79% nitrogen 16% oxygen 5 % carbon dioxide

What are the proportions of gases that exist in the air we breathe in?

79% nitrogen 21% oxygen

Use the Binomial Theorem to determine the probability of two dominant alleles coming together if 80% of the alleles are dominant. - what is the probability that two recessive alleles will come together? - What is the percentage of heterozygotes?

80% are dominant, thus 20% are recessive. - p=.80 - q=.20 - thus, (.80)²= .64. the probability that two dominant alleles come together is 64% The probability of two recessive alleles coming together is (.20)²=.04, so 4% The percentage of heterozygotes is calculated by 2pq, therefore 2x.8x.2= 0.32... Thus, 32% of gametes will be heterozygotes

What are the products of carbohydrate digestion within the alimentary tract?

80% glucose, 20% fructose and galactose. Much of the fructose and galactose ingested by humans is converted into glucose in the liver enterocytes; fructose can enter glycolysis as fructose-6-phosphate, and galactose can be converted to glucose-6-phosphate to enter glycolysis.

How much energy is created per gram of fat?

9 calories

What fraction of offspring are likely to display both dominant phenotypes in a dihybrid cross?

9/16

Where does 90% of digestion and absorption occur?

90% of digestion and absorption occurs in the small intestine

__% of oxygen in the blood binds rapidly and reversibly to hemoglobin.

98%

What is the genotypic ratio of a dihybrid cross?

9:3:3:1 - 9 dominant/dominant - 3 dominant/recessive - 3 recessive/dominant - 1 recessive/recessive - for a dihybrid cross, as long as all F1 progeny are heterozygous for both traits/alleles, the same 9:3:3:1 ratio is observed.

What is the phenotypic ratio of a dihybrid cross?

9:3:3:1 9= dominant in both phenotypes 3= dominant in 1, recessive in 1 3= dominant in 1 and recessive in 1 1= recessive for both phenotypes

The oxygen dissociation curve of Myoglobin exhibits what sort of graph?

A Hyperbolic Dissociation Curve

What is a Mendelian trait?

A Mendelian trait is one that is controlled by a single locus and shows a simple Mendelian inheritance pattern. Mendelian traits follow Mendelian ratios.

What is a Retrovirus?

A Retrovirus contains RNA only and the enzyme Reverse Transcriptase. - They enter the host cell by fusion and use reverse transcriptase to form DNA from their RNA template. - The new DNA is then inserted into the host's genome, which transcribes, translates and assembles new retroviruses. - The new retroviruses exit the host by budding, maturing then infecting new host cells. - HIV is a retrovirus

A blood donor may donate blood only to an individual that does not make ______ against the donor blood.

A blood donor may donate blood only to an individual that does not make antibodies against the donor blood. - therefore, a type A person can only donate blood to a type A person, not to a type O or type B person because both Type B and O produce antibodies against type A.

What may form if the micelle solution is exposed to ultrasonic vibration?

A liposome may form, having aqueous solution inside as well as surrounding it. It will have the double phospholipid bilayer.

What happens when air enters the intrapleural space, and what would cause air to enter this space?

A penetrating injury would cause air to enter the pleural cavity. - When air enters this intrapleural space, the lung collapses because the pressure inside the intrapleural space increases. - This is called pneumothorax.

Does at person weigh more or less at the equator than at the poles?

A person weighs less at the equator, because the radius of Earth is larger at the equator and the spin of the Earth tends to make the person slightly lighter as well.

Phosphatases:

A phosphatase is an enzyme that removes a phosphate group from its substrate by hydrolysing phosphoric acid monoesters into a phosphate ion and a molecule with a free hydroxyl group (see dephosphorylation). This action is directly opposite to that of phosphorylases and kinases, which attach phosphate groups to their substrates by using energetic molecules like ATP. A common phosphatase in many organisms is alkaline phosphatase.

What is the cytosol of nearly all prokaryotes surrounded by?

A phospholipid bilayer called the Plasma Membrane.

What is a portal system?

A portal system is a capillary bed that drains into another capillary bed through a vein, without first going through the heart.

What is the egg called when surrounded by the Zona Pellucida?

A primary follicle.

While the viral DNA is dormant during the lysogenic cycle, in the bacterial host cell's chromosome, being replicated along with the host cell's DNA, what is it called?

A provirus or prophage (if in a bacterium)

What sort of atmosphere existed on early earth?

A reducing atmosphere, where carbon based molecules took little energy to form.

What does Negative feedback provide?

A shutdown mechanism for a series of enzymatic reactions when that series has produced sufficient amount of product.

A single ____ is specific for a single antigen, and a single B lymphocyte produces only one type of _____.

A single antibody is specific for a single antigen, and a single B lymphocyte produces only one type of antibody

Describe why there exists a difference in blood flow velocity through out the body:

A single artery is much bigger than a capillary, but there are far more capillaries than arteries. The total cross-sectional area of all the capillaries put together is much greater than the cross-sectional area of a single aorta or a few arteries. - Blood flow follows the Continuity Equation: Q=AV, so velocity is greatest in the arteries where cross-sectional area is smallest and velocity is lowest where cross sectional area is greatest, as in the capillaries.

How many synapses does a single neuron make?

A single neuron may make from a few to as many as 200,000 synapses. - Most synapses contact dendrites, but some may directly contact other cell bodies, axons, or even other synapses.

Since there is a much lower hydrostatic pressure in the veins, what prevents the back-flow of blood?

A system of valves prevents the back-flow while movement of skeletal muscle provides the force necessary to return blood to the heart. - Contraction of skeletal muscle helps move blood through veins, however, the major propulsive force moving the blood through the veins is the pumping force of the heart.

What does fungi consist of in their growth state?

A tangled mass called mycelium of multiply branched thread-like structures called hyphae. Hyphae are haploid

What sort of cross is used to determine if an individual exhibiting a dominant trait is either homozygous or heterozygous for that trait?

A test cross or back cross: - the test cross involves breeding the individual in question with a homozygous recessive individual. - Thus, the 2 possible outcomes are: 1- All offspring are one colour, indicating that the unknown parent was homozygous dominant for that colour allele. 2- Half are one colour and half are the other colour, indicating that the unknown parent was heterozygous for the allele.

What happens to the trachea as it enters the lungs?

A the trachea approaches the lungs it splits into the left and right bronchi. - each bronchus branches many more times to become tiny bronchioles - bronchioles terminate in tiny grape-like clusters called alveolar sacs, composed of tiny alveoli.

What is the Genotype for each blood type?

A=II or Ii B=II or Ii AB=IaIb O=ii

What is the hormone that stimulates the adrenal cortex to synthesize and release its corticosteroids (Aldosterone and Cortisol)?

ACTH, adrenocorticotropic hormone, released from the anterior pituitary due to some form of stress, stimulates the adrenal cortex to synthesize and release cortisol and aldosterone.

What effect does ADH have on the nephron and at which segment does it have its effect?

ADH acts on the collecting tubule which is a part of the distal tubule (not the collecting duct) to increase the permeability of the cells to water. - Thus is the presence of ADH, water flows from the tubule, concentrating the filtrate.

What are the peptide hormones of the Posterior Pituitary?

ADH; Antidiuretic Hormone Oxytocin

How does a muscle contraction begin?

A muscle contraction begins with an action potential. A neuron attaches to a muscle cell forming a neuromuscular synapse. - The AP of the neuron releases acetylcholine into the synaptic cleft. - The acetylcholine activates ion channels in the sarcolemma of the muscle cell creating an AP. - the AP moves deep into the muscle cell via small tunnels in the membrane of the sarcolemma called T-tubules. - the AP is then transferred to the sarcoplasmic reticulum which then becomes more permeable to Ca²⁺ ions. - The Ca²⁺ ions begin the 5 stage cycle by stimulating troponin to pull tropomyosin away from the active site on actin, thus allowing the myosin globular head to attach to the actin active site

Describe how a muscle uses leverage to create movement:

A muscle uses leverage by applying a force to a bone at its insertion point and rotating the bone in some fashion about the joint. Most lever systems of the body act to increase the required force of a muscle contraction. In other words, a greater force than mg is required to lift a mass m. This is done in order to reduce the bulk of the body and increase the range of movement. If the muscle has a shorter lever arm it is closer to the body, and thus creates less bulk.

What is formed when the sarcomeres are laid end to end?

A myofibril: A myofibril (also known as a muscle fibril) is a basic rod-like unit of a muscle. Muscles are composed of tubular cells called myocytes, also known as muscle fibers, and these cells in turn contain many chains of myofibrils. Myofibrils are composed of long proteins such as actin, myosin, and titin, and other proteins that hold them together. These proteins are organized into thin filaments and thick filaments, which repeat along the length of the myofibril in sections called sarcomeres. Muscles contract by sliding the thin (actin) and thick (myosin) filaments along each other. Actomyosin motors are important in muscle contraction (relying in this case on "classical myosins") as well as other processes like retraction of membrane blebs, filiopod retraction, and uropodium advancement (relying in this case on "nonclassical myosins").

What do some enzymes require in order to reach their optimal activity?

A non-protein component called a cofactor. Cofactors can be organic coenzymes or inorganic metal ions. A cofactor is a non-protein chemical compound that is bound to a protein and is required for the protein's biological activity. These proteins are commonly enzymes, and cofactors can be considered "helper molecules" that assist in biochemical transformations. Cofactors are either organic or inorganic. They can also be classified depending on how tightly they bind to an enzyme, with loosely-bound cofactors termed coenzymes and tightly-bound cofactors termed prosthetic groups. Some sources also limit the use of the term "cofactor" to inorganic substances.[1][2] An inactive enzyme, without the cofactor is called an apoenzyme, while the complete enzyme with cofactor is the holoenzyme

What are the 3 steps by which coagulation occurs?

1. A dozen or so coagulation factors form a complex called Protrombin Activator... this is initiated by platelets adhering to collagen fibres in the connective tissue and releasing substances to make nearby platelets sticky. This forms a plug that provides immediate emergency protection against blood loss. 2. Protrombin activator catalyzes the conversion of prothrombin, a plasma protein, into thrombin 3. Thrombin is an enzyme that governs the polymerization of the plasma protein fibrinogen to fibrin threads that attach to the platelets and form the tight plug. This reinforces the original loose plug created by the platelets. - fibrin is eventually degraded by plasmin to conclude the healing process - this blood clot formation or coagulation begin to appear in seconds in small injuries and 1 to 2 minutes in larger injuries

What are the 3 categories by which Leukocytes can be subdivided into?

1. Agranular Monocytes 2. Granulocytes 3. Agranulocytes

What are the 4 ways material can cross capillary walls?

1. Pinocytosis: In cellular biology, pinocytosis ("cell-drinking", "bulk-phase pinocytosis", "non-specific, non-absorptive pinocytosis", "fluid endocytosis") is a form of endocytosis in which small particles are brought into the cell, forming an invagination, and then suspended within small vesicles (pinocytotic vesicles) that subsequently fuse with lysosomes to hydrolyze, or to break down, the particles. 2. Diffusion or transport through capillary membranes 3. movement through fenestrations in the cells 4. movement between space between cells.

What are the 3 components that blood is separated into via a centrifuge?

1. Plasma, 55% 2. Buffy coat (white blood cells/leukocytes and platelets), <1% 3. Red blood cells or hematocrit, 45%

What surrounds the Loop of Henle and what is its role?

A capillary bed called the vasa recta surrounds the loop of Henle and it helps to maintain the concentration of the medulla.

What are most bacteria wrapped in?

A capsule or slime layer: - capsules protect the bacterium from phagocystosis, desiccation, some viruses, and some components of the immune response of an infected host.

What is a dihybrid cross used to look for?

A dihybrid cross is often used to test for dominant and recessive genes in two separate characteristics. Such a cross has a variety of uses in Mendelian genetics.

What is a dihybrid cross used to test for?

A dihybrid cross is used to test for dominant and recessive genes for two separate characteristics. - a dihybrid cross is a cross between F1 offspring (first-generation offspring) of two individuals that differ in two traits of particular interest.

What does heterozygous refer to?

A diploid organism is heterozygous at a gene locus when its cells contain two different alleles of a gene. Heterozygous genotypes are represented by a capital letter (representing the dominant allele) and a lowercase letter (representing the recessive allele), such as "Rr" or "Ss". The capital letter is usually written first.

A _____ allele specifies the phenotype of the heterozygote, while a ____ allele is only expressed in a homozygous individual carrying two identical copies of the recessive allele.

A dominant allele specifies the phenotype of the heterozygote, while a recessive allele is only expressed in a homozygous individual carrying two identical copies of the recessive allele.

What are the 3 main types of lymphocytes?

1. T cells 2. B cells 3. Natural killer cells

What is a follicle in the ovaries?

A follicle is a multi-layered sac of cells that contains, nourishes and protects an immature primary oocyte.

A group of cell bodies located in the CNS is called a _____; while a group of cell bodies located outside the CNS is called a ______.

A group of cell bodies located in the CNS is called a nucleus; while a group of cell bodies located outside the CNS is called a ganglion, as in the sympathetic chain ganglion outside the spinal cord.

What are the 4 types of lipoproteins?

1. Ver low-density 2. Intermediate-density 3. Low-density 4. high-density

What are the 4 possible functions of muscle contraction?

1. body movement 2. stabilization of body position 3. movement of substance through body(lymphatic and cardiovascular systems) 4. generating heat to maintain body temperature

What is a good example of a cosubstrate?

ATP

What is it called when the threshold stimulus is reached very slowly and the AP is not necessarily created?

Accommodation; If the threshold stimulus is reached, but is reached very slowly, an action potential still may not occur.

What must centripetal acceleration be accompanied by?

According to Newton's second law, an acceleration must be accompanied by a net force, which is the Centripetal Force: Fc=mv²/r=ma. Fc always points towards the centre of the circle as well.

What role does Acetyl CoA have in the CAC/Krebs Cycle?

Acetyl CoA is a coenzyme that transfers two carbons from pyruvate to the 4-carbon oxaloacetic acid to begin the Krebs cycle.

What NT is released from neurons to stimulate a muscle contraction?

Acetylcholine

What NT is used by the pre-ganglionic neurons of the sympa and para NS, and also used by the somatic NS?

Acetylcholine

The sole NT used by the parasympathetic NS is?

Acetylcholine for both the long pre-ganglionic neurons and short post-ganglionic neurons, of the parasympathetic ns.

What NT stimulates all secretions from the cells of the stomach?

Acetylcholine via the parasympathetic NS--- Rest and Digest

The NT used by all pre-ganglionic neurons in the ANS and by post-ganglionic neurons in the parasympathetic system is?

Acetylcholine; they are cholinergic

What is activation and germination of the endospore triggered by?

Activation is triggered by heat and germination is triggered by nutrients

What does the movement of compounds against its electrochemical gradient require?

Active Transport and the expenditure of energy

_____ _____ occurs when several separate species arise from a single ancestral species, such as 14 species of Galapagos finches that all evolved from one ancestor.

Adaptive Radiation

Which Nucleotides pair with eachother?

Adenine + Thymine= 2 h-bonds Guanine + Cytosine= 3 h-bonds

__________ are specialized fat cells whose cytoplasm contains almost nothing but _________.

Adipocytes; triglycerides or triacylglycerols

What are the scenarios in which the oxygen dissociation curve shifts to the left, thereby indicating an increasing of Hemoglobin's affinity for oxygen?

1. Decreased pressure of CO₂ 2. Decreasing temperature 3. Decreasing [H⁺], or increasing pH

What are the 4 aspects of inflammatory response?

1. Dilation of blood vessels 2. Increased permeability of capillaries 3. Swelling of tissue cells 4. Migration of macrophages and granulocytes to the inflamed area where they remove pathogens through phagocytosis.

The main things to remember from the Bohr Effect:

1. High H⁺ concentration in the periphery cause the unloading of O₂ from Hb into the tissue 2. Low H⁺ concentration in the lungs cause the Loading of O₂ into Hb.

What are the 2 types of acquired immunity?

1. Humoral or B-cell immunity 2. Cell-mediated or T-cell immunity

What are the 3 forms in which carbon dioxide is carried by the blood?

1. In physical solution 2. as bicarbonate ion: 10 times as much than any other form 3. in carbamino compounds (combined with hemoglobin and other proteins)

What are the scenarios in which the oxygen dissociation curve shifts to the right, thereby indicating a lowering of Hemoglobin's affinity for oxygen?

1. Increased pressure of CO₂ 2. Increasing temperatures 3. Decreasing pH/Increasing [H⁺] 4. 2,3-BPG

What are the 2 components of the human immune system?

1. Innate Immunity: generalized protection from most invading organisms and toxins 2. Acquired Immunity: protection against specific organisms or toxins, which develops after the body has been first attacked. Includes antibodies and lymphokines

What are the multiple interrelated functions of the lymphatic system?

1. It is responsible for the removal of interstitial fluid from tissues 2. It absorbs and transports fatty acids (chylomicrons) to the circulatory system 3. It transports immune cells throughout the body

What is the process of response from the innate immunity?

1. Macrophages phagocytize 2. Neutrophils phagocytize 3. Eosinophils work against parasitic invasion 4. Basophils release histamine for the inflammatory response 5. Natural Killer cells 6. Mast Cells

1. List the Peptide Hormones and where they are from: 2. List the Steroid Hormones and where they are from: 3. List the Tyrosine Hormones and where they are from:

1. Peptide Hormones: I. Anterior Pituitary gland: FSH, LH, ACTH, HGH, TSH, Prolactin II. Posterior Pituitary gland: ADH and oxytocin III. Parathyroid hormone or PTH IV. Pancreas: glucagon and insulin 2. Steroid Hormones: I. Cortisol (glucocorticoid) and aldosterone (mineral corticoid) of the adrenal cortex II.Estrogen, progesterone and testosterone of the gonads 3. Tyrosine Hormones: I. Thyroid Hormones: T₃ and T₄ II. Catecholamines of the adrenal medulla: Epinephrine/Adrenaline and norepinephrine/noradrenaline

What are the main hormones that affect the secretion of the stomach juices?

- Acetylcholine via the PSN is the main one, increasing the secretion of all cell types in the stomach. - Histamine and Gastrin mainly increase secretion of HCl from parietal cells.

What are the big differences between granulocytes and agranulocytes?

- Agranulocytes live much longer because they work against specific agents of infection, whereas granulocytes function non-specifically against all infective agents. Therefore, agranulocytes need to hang around in case the same infective agent returns; whereas granulocytes multiply quickly against any infection and then die once the infection is gone.

What are the important proteins contained in the blood plasma?

- Albumins: for fatty acid and steroid transport, and regulate osmotic pressure of blood - Immunoglobulins: also called antibodies - clotting factors: like fibrinogen

Describe Blood:

- Blood is a connective tissue, and like any connective tissue it contains cells and a matrix - blood protects the body from injury and foreign invaders

How do myosin and actin produce the contractile force of skeletal muscle?

- Each globular head of the myosin(thick) filament crawls along the actin (thin) filament in a 5 stage cycle: 1- Tropomyosin covers an active site on the actin preventing the myosin head from binding. The myosin head remains cocked in a high energy position with a phosphate and ADP group attached. 2- In the presence of Ca²⁺, troponin pulls the tropomyosin back from the active site of actin, exposing the active site on the actin filament, allowing the myosin globular head to bind to the actin active site. 3- The myosin head expels a phosphate and ADP and bends into a lower energy position, dragging the actin along with it. This is muscle contraction. 4- ATP attaches to the myosin head. This releases the myosin head from the active site of the actin, which is then immediately covered by a tropomyosin. 5- ATP splits to inorganic phosphate and ADP causing the myosin head to cock into the high energy position. This cycle is repeated many times to form a contraction.

Describe the red blood cells of the plasma, also known as the Hematocrit:

- Erythrocytes (red blood cells), are bags of hemoglobin. - they have no organelles - no nucleus thus do not undergo mitosis or reproduce - they are disc-shaped - main function is in O₂ and CO₂ transport

What happens during the Luteal/Secretory phase?

- Following ovulation, LH induces the ruptured follicle to develop into the corpus lutem - The corpus luteum then secretes estrogen and progesterone

What are the Haversian Canals?

- Haversian canals are the tunnels in compact bone created by the burrowing of osteoclasts. - Haversian Canals contain blood and lymph vessels, and are connected by crossing canals called Volkmann's canals.

Describe the structure and composition of hemoglobin:

- Hb is composed of 4 polypeptide subunits, each with a single heme cofactor - there are 2 α-chains and 2 β-chains - the heme cofactor is an organic molecule with an atom of iron at its center - each of the 4 iron atoms in Hb can bind with one O₂ molecule - When one O₂ molecule binds with an iron atom in Hb, oxygenation of the other heme groups is accelerated... this is known as cooperative binding - similarly, release of an O₂ molecule by any of the heme groups in Hb accelerates the release of the others.

What do osteoclasts do to the compact bone?

- In a continuous process, osteoclasts burrow tunnels, called Haversian (central) canals, through compact bone.

Describe the process by which compact bone is produced:

- In a continuous process, osteoclasts burrow tunnels, called Haversian (central) canals, through compact bone. - Then osteoblasts follow the osteoclasts, laying down a new matrix onto the tunnel walls forming concentric rings called lamellae.

Describe X-Linked Dominant Inheritance:

- Mode of inheritance by which a dominant gene is carried on the X-chromosome - affects both sexes, but more females than males - rare type of inheritance - affected male (XAY) x unaffected female (XX):boys will be 100% unaffected (XY), girls will be 100% affected (XAX) - affected male (XaY) x affected female (XAX): boys will be 50% unaffected (XY) and 50% affected (XAY), girls will be 100% affected (50% XAX, 50% XAXA) - affected males (XAY) x affected females (XAXA): boys will be 100% affected (XAY), girls will be 100% affected (XAXA) - affected female (XAX) x unaffected male (XY): boys are 50% affected (XAY) and 50% unaffected (XY), girls are 50% affected (XAX) and 50% unaffected (XX) - affected female (XAXA) x unaffected male (XY): boys will be 100% affected (XAY), girls will be 100% affected (XAX) - example is Aicardi Syndrome

Describe the functions of the Smooth ER:

- SER contains glucose-6-phosphatase, the enzyme used in the liver, intestinal epithelial cells, and renal tubules epithelial cells to hydrolyze glucose-6-phosphate to glucose, an important step in the production of glucose from glycogen. - SER produces triglycerides, then are stored in fat droplets. - cholesterol formation and subsequent conversion to steroids. - most of phospholipids in the cell membrane are synthesized in the SER. - SER oxidizes foreign substances, detoxifying drugs, pesticides, toxins, and pollutants.

What are the conventional symbols used in a pedigree?

- Squares= males - circles=females - solid circle/square= affected individual - blank circle/square= unaffected individual - known carriers are represented by a single line or half shaded in circle/square - Horizontal lines represent mating - vertical lines represent a given generation

Describe the process by which a peptide hormone is produced and activated:

- Synthesized in the RER as preprohormones - Preprohormones are cleaved into prohormones, and move to the golgi apparatus from the RER for modification into peptide hormones - Peptide hormones are packaged into secretory vesicles for release via exocytosis and remain water soluble in the blood - they act on effector cell membrane receptors and initiate internal secondary messenger cascades.

What effects does TSH have on the thyroid?

- TSH causes the thyroid to release T3 and T4 - TSH increases thyroid cell size - TSH increases thyroid cell number - TSH increases thyroid rate of secretion of T3 and T4 - TSH stimulates thyroid to absorb more iodine

What are the effects of testosterone on the body?

- Test is the primary androgen or male sex hormone - it stimulates the germ cells to become sperm - it is responsible for the development of the secondary sex characteristics such as pubic hair, enlargement of the larynx, growth of penis and seminal vesicles. - it initiates the growth spurt at puberty and it also stimulates the closure of the epiphyses of the long bones, ending growth in stature.

Describe how the Bohr Effect plays a role in oxygen loading and unloading:

- The Bohr effect is an allosteric relationship between CO₂, H⁺, and O₂. - High concentrations of CO₂ in the periphery tissue cause the CO₂ to diffuse into the erythrocyte, i combines with H₂O to form Carbonic Acid (H₂CO₃) which is then dissociated into bicarbonate ion and H⁺. This increase in H⁺ ions creates a decrease in pH→ This causes O₂ unloading in peripheral tissue, because the H⁺ binds to hemoglobin, releasing O₂ bound by Hb to the peripheral tissue - The HbH⁺ (hemoglobin with H⁺) now created has a high affinity for CO₂, thus the HbH⁺ molecule now picks up CO₂... 20% of CO₂ is transported through blood this way - HCO⁻₃ diffuses into the blood and is transported back to lungs... this is how 80% of the CO₂ is transported. - In the lungs, a high oxygen partial pressure leads to oxygenation of Hb and release of H⁺ and CO₂ from Hb (Haldane Effect) - CO₂ is directly expelled from the erythrocyte and the H⁺ combines with HCO⁻₃ to form H₂CO₃ (carbonic acid) inside the erythrocyte.... This increases pH by lowering H⁺ ion concentration... thus, since pH is increased, Hb has higher affinity for O₂, thus there is a lot of O₂ bound to Hb - Carbonic Anhydrase catalyzes the conversion of carbonic acid (H₂CO₃) to CO₂ and H₂O, which are then exhaled by the lungs.

During muscle contraction, which bands get smaller and which do not change size?

- The H zone and I band get smaller - The A band does not change size - the I band gets smaller as the ends of the myosin filaments of adjacent sarcomeres get closer upon contraction - the H zone gets smaller as the ends of actins filaments within the same sarcomere get closer together - the A band is essentially the length of the myosin filaments from end to end within a single sarcomere, thus that length never changes, as the myosin filaments do not contract or expand.

What is the Rh factor?

- The Rh factor is a specific antigen, D antigen, present on the surface of red blood cells. - Rh factors are surface proteins on red blood cells. An individual either has, or does not have, the "Rhesus factor" on the surface of their red blood cells. This term strictly refers only to the most immunogenic D antigen of the Rh blood group system, or the Rh- blood group system. The status is usually indicated by Rh positive (Rh+ does have the D antigen) or Rh negative (Rh- does not have the D antigen) suffix to the ABO blood type. However, other antigens of this blood group system are also clinically relevant. These antigens are listed separately (see below: Rh nomenclature). In contrast to the ABO blood group, immunization against Rh can generally only occur through blood transfusion or placental exposure during pregnancy in women.

Describe what is known about the process of HCl production within the parietal cells:

- The amount of energy needed is great, thus there is an abundance of mitochondria - carbon dioxide is involved in the process, making carbonic acid inside the parietal cell. - The hydrogen from the carbonic acid is expelled to the lumen of the stomach, while the bicarbonate ion is expelled into the interstitial fluid side of the parietal cell.

What are the differences between the sympathetic and parasympathetic post and pre-ganglionic neurons?

- The cell bodies of the sympathetic post-ganglionic neurons lie far from their effector organs, generally within the paravertebral ganglion or sympathetic chain ganglion, that runs parallel to the spinal cord on both sides, or within the prevertebral ganglion in the abdomen. - Therefore, the sympathetic pre-ganglionic neurons run from the spinal cord to the sympathetic chain ganglion, then the post-ganglionic neurons run from the sympathetic chain ganglion to the effector organ. - The cell bodies of the parasympathetic postganglionic neurons lie in ganglia close to or on the effector organs. - the parasympathetic pre-ganglionic neurons are long, extending from the spinal cord to very near the effector organ.

Describe the white blood cells(leukocytes) and their role in the body:

- White Blood Cells/Leukocytes contain organelles - They do NOT contain Hb - they play a vital role in the immune response

Describe Y-Linked Inheritance:

- affects only males who always have an affected father, unless there is a new mutation - very rare type of inheritance - Example is hairy ears

Describe Autosomal Dominant Inheritance:

- alleles are found on the autosomal chromosomes, 1-22. - an affected person (AA or Aa) usually has at least one affected parent (AA or Aa). - equally transmitted by either sex - child of an affected (often heterozygous, Aa) x an unaffected mating (aa) has a 50% chance of being affected. - Child of an affected x affected has a 75% chance of being affected. - examples are Huntington's and Neurofibromatosis-1 - often includes late onset diseases, therefore there is little chance for diagnosis before mating

How does sexual reproduction occur in fungi?

Between hyphae from two mycelia of different mating types + and -. These two hyphae grow towards eachother, eventually touching and forming a conjugation bridge. - The tip of each hypha forms a complete septum in all divisions of fungi, and becomes a gamete-producing cell called a gametangium. - the gametangium remain attached to the hyphae and the nuclei fuse with one another to form a diploid zygote, called a zygospore. - The zygospore separates from the parent hyphae and usually enters a dormant phase. When activated by the appropriate conditions, the zygospore undergoes meiosis to produce haploid cells, one of which immediately grows a short sporangiophore to asexually reproduce many spores.

Where is the periplasmic space in gram negative bacteria?

Between the two phospholipid bilayers, it encompasses the PD wall.

SInce carbonic anhydrase is inside the red blood cell and not free in the plasma, when CO₂ is absorbed in the lungs, _____ ion diffuses into the red blood cell. Why?

Bicarbonate ion diffuses into the cell in order to allow the reverse reaction of carbonic anhydrase. This creates H₂O and CO₂, wherein the CO₂ diffuses out of the cell and is exhaled out of the lungs.

How does bile increase surface area of the fat?

Bile emulsifies the fat, which means that it breaks it up into small particles without changing it chemically. This increases the surface area of the fat, allowing the lipase to degrade it into mainly fatty acids and monoglycerides.

How is fat digested in the duodenum?

Bile salts emulsify cholesterol, phospholipids and triglycerides into micelles. - lipase hydrolyzes triglycerides into fatty acids - monoglycerides and fatty acids are shuttled to the brush border within the micelles.

_____ also contains bilirubin, an end product of hemoglobin degradation.

Bile, - bilirubin is what gives the bile a dark red almost brown colour.

What is exponential growth in bacteria due to?

Binary Fission

____ _____ is a type of asexual reproduction which bacteria are capable of, in which the circular DNA is replicated in a process similar to replication in eukaryotes. Two DNA polymerases begin at the same point on the circle (origin of replication) and move in opposite directions making complementary single strands that combine with their template strands to form two complete DNA double stranded circles. The cell then divides, leaving one circular chromosome in each daughter cell. The 2 daughter cells are genetically identical.

Binary Fission

_____ neurons are found in the retina, inner ear, olfactory area of the brain.

Bipolar

What is the fluid filled cavity in the blastocyst called?

Blastocoel

Formation of the inner cell mass?

Blastulation

Novocain acts as a local anesthetic by doing what?

Blocking sodium voltage gated channels, the only was to prevent/block an AP.

Describe the path of blood into the Nephron:

Blood flows from the renal artery into the first capillary bed of the nephron called the Glomerulus, which is part of the renal corpuscle. - Hydrostatic pressure forces some plasma through fenestrations of the glomerular endothelium and into Bowman's capsule - The fluid that enters Bowman's capsule is called filtrate or primary urine - This filtrate moves from Bowman's capsule to the Proximal tubule. - the capillary bed known as the Glomerulus is located within Bowman's capsule. So once the filtrate passes through the glomerulus, it enter the cavity of Bowman's capsule

List the circulatory pathway of blood:

Blood from body→superior and inferior vena cava→right atrium→tricuspid valve→right ventricle→pulmonary valve→pulmonary artery→lungs→pulmonary vein→left atrium→mitral valve→let ventricle→aortic valve→aorta→Blood to body

What type of compounds are easily dissolved in the blood and why?

Blood is an aqueous solution an only hydrophilic compounds are easily dissolved

What force propels the blood through the cardiovascular system?

Blood is propelled through the system by the hydrostatic pressure created by the contraction of the heart.

What happens to the blood when the liver uses fat or protein for energy production?

Blood pH decreases or acidity increases

Blood pressure ____ near the heart and ____ to its lowest in the capillaries.

Blood pressure increases near the heart and decreases to its lowest in the capillaries. - Blood pressure deceases from the arteries to the capillaries and then stays constant in the venules and veins.

Describe the changes in blood pressure through out the areas of the systemic circulation, starting with the Aorta:

Blood pressure is highest in the aorta and slowly decreases through the large arteries, small arteries and then plunges through the arterioles and capillaries. - Blood pressure reaches its lowest in the venules and small veins. - BP stays at its lowest through the large veins to the vena cava, then it increases a little through the pulmonary arteries, arterioles. - After the pulmonary arterioles, BP starts to decreases again into the pulmonary capillaries, venules and veins.

What are the factors that affect interstitial pressure?

Blood pressure, plasma osmotic pressure, interstitial osmotic pressure (from proteins, infection response, etc), permeability of capillaries

How are blood types identified?

Blood types are identified by the A and B surface antigens. - for instance, Blood type A means that the RBC membrane has A antigens and does not have B antigens. Thus, if the erythrocyte has A antigens, the immune system does NOT make A antibodies or this would be an autoimmune disease

Blood velocity decreases going from ____ to ____ and then increases going to ___ and ___.

Blood velocity decreases going from arteries to capillaries and then increases going to venules and veins.

What comprises the renal corpuscle?

Bowman's Capsule and the Glomerulus

How is cardiac muscle shaped?

Branched

What does acetylcholinesterase do?

Breaks down acetylcholine

What is breathing dependent on?

Breathing is dependent on pressures changes inside the thoracic cavity (body cavity containing the lungs and heart), which is separated from the abdominal cavity via the diaphragm

What is the motion called by which the NTs diffuse across the synaptic cleft?

Brownian Motion- the random motion of molecules

How do bacteria change direction of motion?

Bacteria will rotate their flagella CW in order to tumble, which acts to change the orientation of the bacterium allowing it to move forward in a new direction.

What types of invaders is Humoral immunity effective against?

Bacteria, Fungi, parasitic protozoans, viruses and blood toxins

______ _____ is the transfer of genetic material between bacterial cells by direct cell-to-cell contact.

Bacterial Conjugation: requires that one of the bacterium have a plasmid with the gene that codes for the sex pilus, the F+ gene or F plasmid. A plasmid that contains the gene for the sex pilus is called a conjugative plasmid - the passage of DNA is always from the cell containing the conjugative plasmid (F+) to the cell that does not.

What are antibodies and what do they do?

An antibody (Ab), also known as an immunoglobulin (Ig), is a large Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, called an antigen. Each tip of the "Y" of an antibody contains a paratope (a structure analogous to a lock) that is specific for one particular epitope (similarly analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by other parts of the immune system, or can neutralize its target directly (for example, by blocking a part of a microbe that is essential for its invasion and survival). The production of antibodies is the main function of the humoral immune system.

____ ______ occurs when the capsid of a bacteriophage mistakenly encapsulates a DNA fragment of the host cell and upon infecting a new bacterium, they inject the harmless bacterial DNA fragments instead of virulent viral DNA fragments.

Bacterial Transduction: - the virus that mediates transduction is called a vector.

_____ ______ is the process by which bacteria may incorporate DNA, often in the form of plasmids, from their external environment into their genome.

Bacterial Transformation: - Ex) when heat killed virulent bacteria are mixed with living, non-virulent bacteria. The result is that the living, non-virulent bacteria take up the DNA around them and become virulent via transformation

How do bacterial and eukaryotic flagella differ?

Bacterial flagella are long, hollow, rigid, helical cylinders made from a globular protein called flagellin. Eukaryotic flagella is composed of microtubules

What is the purpose of Bacterial flagella?

Bacterial motion: - they rotate CCW, looking at the cell from the outside, to propel the bacterium in a single direction

What happens to the viral genetic material once inserted into a bacterium?

Bacterial ribosomes then replicate, transcribe and translate the viral DNA. New virions are assembled within the host cell and the phages are released by cell lysis, extrusion or budding.

What is a virus that injects bacteria called?

Bacteriophage or phage

The ____ _____ or _____ _____ is a thin sheet of matrix material that separates epithelial cells from support tissue.

Basal lamina or basement membrane. - Epithelial cells separate the outside environment from the inside environment of the body. Support tissue is composed of the cells adjacent to the epithelial cells on the inside of the body. - Basal lamina is also found around nerves, muscle and fat cells - The basal lamina acts as a sieve type barrier, selectively allowing the passage of some molecules but not others.

How can we classify all organisms?

Based on how the acquire carbon and energy

How are the proteins distinguished from one another by the golgi?

Based on their signal sequence and carbohydrate chains. Those proteins not possessing a signal sequence are packaged into secretory vesicles and expelled from the cell in a process called bulk flow.

______ release many of the chemicals of the inflammation response.

Basophils

What is an antigen and what does it do?

An antigen is a substance that evokes the production of one or more antibodies. Each antibody binds to a specific antigen by way of an interaction similar to the fit between a lock and a key. The substance may be from the external environment or formed within the body. The immune system will try to destroy or neutralize any antigen that is recognized as a foreign and potentially harmful invader. The term originally came from antibody generator and was a molecule that binds specifically to an antibody, but the term now also refers to any molecule or molecular fragment that can be bound by a major histocompatibility complex (MHC) and presented to a T-cell receptor. "Self" antigens are usually tolerated by the immune system, whereas "non-self" antigens can be identified as invaders and can be attacked by the immune system.

When did photosynthesis develop?

Around 2.3 bya, the ancestors to cyanobacteria formed. - they were able to use sunlight and water to reduce carbon dioxide. - they were the first oxygen producing, photosynthetic bacteria. - this led to the atmosphere filling with oxygen and the oxygenation of the planet around 2.3 bya.

____ are wrapped with smooth muscle that is typically innervated by the sympathetic nervous system.

Arteries

______ move blood away from the hear, are elastic, stretch when filled with blood, and are wrapped in smooth muscle for vasoconstriction-innervated by the sympathetic nervous system.

Arteries

_____ are elastic and stretch as they fill with blood.

Arteries: - as the ventricles finish their contraction, the stretched arteries recoil, keeping the blood moving more smoothly.

What are the main mechanism used to regulate blood pressure and reroute blood?

Arterioles

_____ are very small. They are wrapped by smooth muscle. Constriction and dilation of _____ can be used to regulate blood pressure as well as rerouting blood.

Arterioles

______ control where blood flows, are smaller arteries with more smooth muscle wrapped around them. Constriction and dilation are used to regulate blood pressure and to reroute blood flow.

Arterioles

What is the Chlorine Shift?

As bicarbonate ion diffuses into the RBC in the capillaries of the lungs, Cl⁻ ions diffuse out of the erythrocyte in order to balance the electrostatic forces. - This is the process of the Bohr Effect wherein H₂O and CO₂ are produced and released from the cell to be exhaled by the lungs

How do lipoproteins change as the density increases?

As density increases, first the amount of triglycerides decrease, then the amount of cholesterol and phospholipids decrease. Thus, VLDL have a lot of triglycerides while HDL have very few triglycerides.

How are triacylglycerides transported?

As lipoproteins (small chylomicrons) which can either be very low-density, intermediate density, low-density, or high-density lipoproteins.

What happens to platelets as they come in contact with an injured endothelium?

As platelets come into contact with an injured endothelium, they become sticky and begin to swell, releasing various chemicals and activating other platelets. - the platelets then stick to the endothelium and to each other, forming a loose platelet plug...coagulation

What happens to nitrogen levels as people go scuba diving?

As pressure increases with depth, more nitrogen diffuses into the blood. - When divers come back to the surface, pressure decreases and thus the gas volume of nitrogen increases. - If they do not allow enough time for nitrogen to diffuse out of the blood and into the lungs, the nitrogen will form bubbles. - these bubbles block the vessels causing decompression sickness, also known as "the bends"

Since essential amino acids must be ingested because they cannot be synthesized by the body, in what form do these amino acids enter the blood stream?

As single amino acids

How is the Oxygen dissociation curve affected with an increase in temperature?

As temperature increases, the curve is shifted to the right, indicating a lowered affinity for O₂.

Describe what happens to the lens as the ciliary muscles contract or relax.

As the ciliary muscles contract, the opening of the circle decreases allowing the lens to become more like a sphere and bringing its focal point closer to the lens. As the ciliary muscles relax, the lens flattens increasing its focal distance.

How does glucose leave the enterocyte and enter the blood?

As the concentration of glucose inside the cell builds, it moves out of the cell on the basolateral side via facilitated transport; by a transport protein that goes down its concentration gradient.

What happens to the cells of the embryo as the embryo develops past the eight cell stage of the morula?

As the embryo develops past the 8 cell morula, the cells become different from each other due to a specialized developmental path called determination. - Cells become determined to give rise to a particular tissue early on.

What do the follicles secrete as the grow during the proliferative/follicular phase?

As the follicles grow they secrete estrogen

Describe how enzymes exhibit saturation kinetics:

As the relative concentration of substrate increases, the rate of the reaction also increases, but to a lesser and lesser degree until a maximum rate (Vmax) is achieved. This occurs because as more substrate is added, the individual substrates must begin to wait in line for a free enzyme.

A spermatid has the characteristics of a typical cell, though as it becomes a spermatozoon, it .....?

As the spermatid becomes a spermatozoon, it loses its cytoplasm and forms the head, midpiece, and tail. - The head is composed of the acrosome (enzymes to break membrane of egg down) and the nuclear material. - The acrosome contans lysosome-like enzymes for penetrating the egg during fertilization. - The midpiece contains many mitochondria to provide energy for the movement of the tail.

What happens at high concentrations of lumenal glucose?

At high concentrations of lumenal glucose, glucose will build up in the paracellular (between cells) space between enterocytes and raise osmotic pressure there. - Therefore, the aqueous solution of the lumen will then be dragged into the paracellular space pulling glucose along with it. Glucose is absorbed by this second method only when present in high concentrations.

What happens to endogenous levels of 2,3-BPG/DPG at higher altitudes?

At higher altitudes endogenous levels of 2,3-DPG/BPG increase to facilitate better release of oxygen within the tissues. - Thus, people who live at higher altitudes have greater amounts of it in their blood

What happens to the follicle at ovulation?

At ovulation the mature ovarian follicle bursts and releases its secondary oocyte

How and when are the eggs stimulated for growth?

At puberty, FSH stimulates the growth of the granulosa cells around the primary oocyte. The granulosa cells secrete a viscous substance around the egg called the zona pellucida.

At some stage of a chordates embryonic development, they possess a ______, which is an embryonic axial support, not the backbone, ____ _____, and a dorsal, hollow ___ ___, and a ____.

At some stage of a chordates embryonic development, they possess a notochord, which is an embryonic axial support, not the backbone, pharyngeal slits(gills), and a dorsal, hollow nerve cord, and a tail.

Where does the AP originate?

At the axon hillock

The ____ or ____ is the skin and cartilage flap commonly called the ear.

Auricle or pinna

Under certain conditions lysosomes will rupture and release their contents into the cytosol killing the cell in a process called _______.

Autolysis; - Autolysis is useful in the formation of certain organs and tissues, like the destruction of the tissue between the digits of a human fetus in order to form fingers.

The ______ NS is involuntary and innervates cardiac and smooth muscle, and some glands.

Autonomic

Why is LDL called "bad cholesterol"?

Because LDL particles can also transport cholesterol into the artery wall, retained there by arterial proteoglycans and attract macrophages that engulf the LDL particles and start the formation of plaques, increased levels are associated with atherosclerosis. Over time vulnerable plaques rupture, activate blood clotting and produce arterial stenosis, which if severe enough results in heart attack, stroke, and peripheral vascular disease symptoms and major debilitating events.

Why are changes in the spike proteins common in RNA viruses?

Because PNA polymerase does not contain a proofreading mechanism

Why are human blood type alleles considered co-dominant?

Because a heterozygote with alleles for both A and B antigens will exhibit both A and B antigens on the blood cell membranes.

Why do chemoautotrophs require large amounts of substrate?

Because chemoautotrophy is an inefficient mechanism for acquiring energy. Thus they have a large environmental impact. All known chemoautotrophs are prokaryotes.

Why is the entire circulatory system said to be a closed circulatory system?

Because there are no openings for the blood to the leave the vessels.

Why do lipids make such good barriers, separating aqueous environments?

Because they are hydrophobic and repel water. The amphiphilic nature of some lipids allows them to form structures such as vesicles, liposomes, or membranes in an aqueous environment. Amphiphilic means that they have both a hydrophobic end and a hydrophilic end.

Why dont allosteric enzymes exhibit typical kinetics?

Because they normally have several binding sites for different inhibitors, activators, and even substrates.

Why do viruses most closely resemble parasites?

Because they reproduce at the expense of a host. They are not living so they do not use any type of respiration They require no nutrients, using only ATP acquired by their host cell They cannot reproduce inside non-living organic matter

What lies beneath the skin?

Beneath the skin is a subcutaneous tissue called the superficial facia or hypodermis. - the fat of this subcutaneous layer is an important heat insulator for the body. The fat helps maintain normal core body temps on cold days while the skin approaches the temp of the environment.

What types of linkages exist in cellulose?

Beta-linkage, which animals cannot break down. Animals have the enzymes to break the alpha linkages of starch and glycogen, but not the beta linkages of cellulose. Cellulose has beta-(1-4) glycosidic bonds.

_____ are also incapable of mitosis. They exchange nutrients and waste materials with the blood.

Osteocytes: - a star shaped cell, is the most commonly found cell in mature bone, and can live as long as the organism itself. - they do not divide, and they are derived from osteoprogenitors, some of which differentiate into active osteoblasts.[1] In mature bone, osteocytes and their processes reside inside spaces called lacunae and canaliculi, respectively.[1] Cells contain a nucleus and a thin ring of cytoplasm. When osteoblasts become trapped in the matrix they secrete, they become osteocytes. Osteocytes are networked to each other via long cytoplasmic extensions that occupy tiny canals called canaliculi, which are used for exchange of nutrients and waste through gap junctions. The space that an osteocyte occupies is called a lacuna (Latin for a pit).

_______, or outcrossing, is mating of non-relatives which produces hybrids or heterozygotes.

Outbreeding

What is the production of ATP via the ETC called?

Oxidative phosphorylation

Life originated on Earth in an atmosphere with little or no ____?

Oxygen

How is oxygen transported through out the body?

Oxygen is transported through out the body, from the lungs to the peripheral tissue via hemoglobin.

_____ is formed when oxygen binds to the hemoglobin protein inside the erythrocytes.

Oxyhemoglobin

_______ is a small peptide hormone, released from the posterior pituitary that increases uterine contractions during pregnancy and causes milk to be ejected from the breasts.

Oxytocin

In which direction does Carbonic Anhydrase function in body tissue?

CO₂ + H₂O →(via Carbonic anhydrase) H₂CO₃→ HCO⁻₃ + H⁺ - thus, CO₂ from tissues causes the decrease of blood pH. - In tissues, carbonic anhydrase creates HCO⁻₃ and H⁺ ions, thereby making blood more acidic

Why must there exist a balance between calcitonin and PTH?

PTH and calcitonin must act antagonistically to each other in order to maintain calcium homeostasis in the blood and bones. - there must be a calcium homeostasis in the blood of 9-11mg/100ml.

Why do people who drink beer or caffeine containing coffee or tea frequently need to urinate?

Caffeine and beer are ADH blockers. - ADH increases water permeability and water reabsorption back into the blood by increasing the number of aquaporins in the collecting ducts. - Caffeine and beer block the translocation of aquaporins to the collecting ducts, therefore the body is unable to remove water from the collecting ducts and the urine is highly diluted. - Therefore, caffeine and beer increase urine volume by diluting it and preventing ADH from placing aquaporins in the collecting duct's plasma membranes to reabsorb water to the blood.

_____ is a large peptide hormone released by the thyroid.

Calcitonin

What is the main effect of calcitonin?

Calcitonin decreases blood calcium levels by decreasing osteoclast activity and number. In other words, calcitonin inhibits the release of calcium from bone by osteoclasts. - Calcium levels can be effectively controlled in humans in the absence of calcitonin.

What are the effects of PTH on the body?

Calcium: 1- PTH increases blood calcium levels by stimulating osteoclasts to break down bone and release calcium. 2- PTH also increases gastrointestinal calcium absorption by activating vitamin D, and promotes calcium conservation (reabsorption) by the kidneys. Phosphate: - PTH is the major regulator of serum phosphate concentrations via actions on the kidney. It is an inhibitor of proximal and also distal tubular reabsorption of phosphorus. Through activation of Vitamin D the absorbtion of Phosphate is increased.

What is the function of Calsequestrin and where is it found?

Calsequestrin is found in the lumen of the sarcoplasmic reticulum, and it binds Ca²⁺ ions in order to lower the free calcium ion concentration inside the lumen of the sarcoplasmic reticulum.

______ are microscopic blood vessels usually only one cell thick. They are the site of nutrient and gas exchange. They have no smooth muscle.

Capillaries

Summarize the path of carbohydrates starting in the intestinal lumen of the small intestine:

Carbohydrates are digested by pancreatic amylase in the brush border of the duodenum. The resulting sugars travel through the apical side of the enterocyte, out the basolateral side and into the blood. They then travel through the portal vein into the liver.

What happens when cells reach their saturation point with glycogen?

Carbohydrates will be converted to fatty acids and then to triglycerides in a process requiring a small amount of energy. - thus, when the glycogen stores are full, glucose is then stored as fat which is a long-term form of energy storage.

What effect does Carbon Monoxide have on the oxygen dissociation curve?

Carbon Monoxide has more than 200 times greater affinity for Hb than does oxygen but it shifts the curve to the left.

Which enzyme governs the formation of bicarbonate ion?

Carbonic anhydrase in the reversible reaction: CO₂ + H₂O → HCO⁻₃ + H⁺ This creates the Bohr Effect

Can cardiac muscle grow?

Cardiac muscle can grow via hypertrophy

What is the role of the intercalated disc within the cardiac muscle?

Cardiac muscle consists of single heart muscle cells (cardiomyocytes) which have to be connected by intercalated discs to work as a functional organ. By contrast, skeletal muscle consists of multinucleated muscle fibers and therefore exhibit no intercalated discs. Intercalated discs support synchronised contraction of cardiac tissue. They can easily be visualized by a longitudinal section of the tissue.

Is cardiac muscle voluntary or involuntary?

Cardiac muscle is involuntary

The bolus moves into the stomach from the esophagus through the _____ _____.

Cardiac sphincter or lower esophageal sphincter.

Describe Cardiac muscle cells:

Cardiomyocytes have a single nucleus, a sarcolemma, sarcoplasmic reticulum, and transverse tubules.

Is cartilage vascular and if so, what part of it is vascular?

Cartilage is avascular, contains no blood vessels or nerves except in its outside layer called the perichondrium.

What is cartilage composed of?

Cartilage is composed of collagen thus has great tensile strength. - Cartilage is composed of specialized cells called chondroblasts that produce large amounts of extracellular matrix composed of collagen, proteoglycan and elastin fibres.

What is Cartilage?

Cartilage is flexible, resilient connective tissue. - is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the bronchial tubes and the intervertebral discs. It is not as hard and rigid as bone but is stiffer and less flexible than muscle. - Cartilage is composed of specialized cells called chondroblasts that produce a large amount of extracellular matrix composed of collagen fibers, abundant ground substance rich in proteoglycan, and elastin fibers. Cartilage is classified in three types, elastic cartilage, hyaline cartilage and fibrocartilage, which differ in the relative amounts of these three main components.[1] Chondroblasts that get caught in the matrix are called chondrocytes. They lie in spaces called lacunae with up to eight chondrocytes per lacuna. Unlike other connective tissues, cartilage does not contain blood vessels. The chondrocytes are supplied by diffusion, helped by the pumping action generated by compression of the articular cartilage or flexion of the elastic cartilage. Thus, compared to other connective tissues, cartilage grows and repairs more slowly.

_____ joints allow little to no movement. They occur between two bones tightly connected by _____, such as the ribs and the sternum, or the pubic symphysis in the hip bone.

Cartilaginous joints allow little to no movement. They occur between two bones tightly connected by cartilage, such as the ribs and the sternum, or the pubic symphysis in the hip bone.

What hormones are produced in the adrenal medulla?

Catecholamines: Epinephrine and norepinephrine

What are the main structural features of neurons?

Cell body or soma Dendrites Axon with many small branches

Describe Cell-Mediated immunity and how it works:

Cell-mediated immunity involves T-Lymphocytes - T lymphocytes mature in the thymus - T lymphocytes have an antibody-like protein at their surface that recognizes antigens. - T lymphocytes never make free antibodies - In the thymus, T lymphocytes are tested against self-antigens, which are antigens expressed by normal cells of the body - If the T lymphocyte binds to a self-antigen, the T lymphocyte is destroyed in order to prevent auto-immune diseases - If it does not bind to a self-antigen, it is released to lodge in lymphoid tissue or to circulate between the blood and lymph fluid - T lymphocytes that are not destroyed, differentiate into Helper T cells, Memory T cells, Suppressor T cells and Killer T cells(also called Cytotoxic T cells) - The T helper cells assist in activating B lymphocytes as well as killer and suppressor T cells. - An infected cell signals for its own death by presenting some of the antigen on its surface through the class I MHC molecule and then its destroyed by an activated cytotoxic T cell

______ (the polysaccharide making up the cell wall of plants) cannot be digested by humans, and is considered roughage.

Cellulose

The _____ Nervous System consists of the interneurons and the support tissue within the brain and the spinal cord.

Central

What are the two major divisions of the nervous system?

Central nervous system and the peripheral nervous system.

______ function in the production of flagella and cilia, but are not necessary for microtubule production.

Centrioles: are 9+2 microtubule

The ______ is the major MTOC in animal cells.

Centrosome

What are ceruminous glands and where are they found?

Ceruminous glands produce the wax-like material in the ears.

Where does chemical digestion begin and what is digested?

Chemical Digestion begins in the mouth as α-amylase begins to breakdown the long straight chains of starch, contained in the carbohydrates, into polysaccharides.

What is the process by which neutrophils are drawn towards injured or infected tissues?

Chemotaxis

_____ cells are found deep within the exocrine glands/gastric pits. They secrete pepsinogen, the zymogen precursor to pepsin.

Chief cell or peptic cells.

In _______, the heterozygote fully expresses the phenotype of both of the alleles. There is no intermediate phenotype.

Co-dominance

The genes that produce the A and B antigens are ____.

Co-dominant, thus an individual having the type A or B blood may be heterozygous or homozygous.

What did the first cells evolve from?

Coacervates, which are lipid or protein bilayer bubbles. - A coacervate is a tiny spherical droplet of assorted organic molecules (specifically, lipid molecules) which is held together by hydrophobic forces from a surrounding liquid. - they spontaneously form and grow from fat molecules suspended in water

Alleles are said to be _____, when the heterozygote exhibits both phenotypes.

Codominant

Chordates also have a _____, which is a body cavity within the mesodermal tissue.

Coelom

What are coenzymes and what 2 groups can they be divided into?

Coenzymes are: loosely bound cofactors in a protein. They are divided into co-substrates and prosthetic groups. Prosthetic groups are tightly bound cofactors. Both are organic molecules Cosubstrates reversibly bind to a specific enzyme, and transfer some chemical group to another substrate.

How do collagen fibres add tensile strength to bones?

Collagen fibres lie along the line of tensile force of the bone, giving the bone great tensile strength.

____ is the structural protein that gives cartilage and bone their tensile strength.

Collagen.

When a symbiosis is beneficial for one species but does not affect the other, it is called ____?

Commensalism

____ bone is highly structured and vascular and is organized by the Haversian System.

Compact Bone

What type of bone surrounds the medullary cavity or marrow cavity of long bone?

Compact bone surrounds the medullary cavity, which holds the yellow bone marrow. - compact bone is highly organized

Compete with substrate by binding reversibly with non-covalent bonds to the active site:

Competitive Inhibitors -bind to active site for fraction of a second, thus blocking the substrate from binding for only that time. Though, if the substrate binds first, it blocks the inhibitor.

____ dominance is when for any one trait, a diploid individual will have two chromosomes each containing a separate gene that codes for that specific trait.

Complete Dominance - these two chromosomes are homologous by definition. Their corresponding genes are located at the same locus or position on respective chromosomes. Each genes contributes an allele to the genotype. However, only one allele is expressed; if both alleles are dominant, then the dominant phenotype is expressed; if both alleles are recessive, then the recessive phenotype is expressed.

What are proteins containing nonproteinaceous components called?

Conjugates proteins

What results from excessive water reabsorption in the large intestine?

Constipation

____ ____ is the process wherein secretory vesicles are continuously released by most cells.

Constitutive secretion

How do control proteins regulate enzyme activity?

Control proteins are protein subunits that associate with certain enzymes to activate or inhibit their activity. Calmodulin or G-proteins are typical examples of control proteins.

______ evolution is when two species independently evolve similar structures. These structures are said to be analogous structures or homoplastic structures.

Convergent: - an example of convergent evolution is the wings evolved by bats and birds; the two do not share a common ancestor from which they received their wings.

What is Cooperative Binding?

Cooperative binding is a special case of allostery. Cooperative binding requires that the macromolecule have more than one binding site, since cooperativity results from the interactions between binding sites. If the binding of ligand at one site increases the affinity for ligand at another site, the macromolecule exhibits positive cooperativity. Conversely, if the binding of ligand at one site lowers the affinity for ligand at another site, the protein exhibits negative cooperativity. If the ligand binds at each site independently, the binding is non-cooperative. - Hb exerts cooperativity, in that as soon as one O₂ molecule binds to heme in Hb, binding at the other 3 heme sites increases in ease and speed. - conversely, once one heme group loses an O₂ molecule, it becomes easier for the other 3 heme groups to loses their O₂ molecules.

What is the third type of hormone released from the Adrenal Cortex?

Cortical Sex hormones; Androgens; - as steroid based hormones, cortical sex hormones/androgens are responsible for secondary sexual characteristics and can produce masculinizing effects in women.

Which hypothalamus hormone stimulates the anterior pituitary to release ACTH?

Corticotropin releasing hormone, CRF

_____ is a stress hormone and it diminishes the capacity of the immune system to fight infection.

Cortisol

What effect does cortisol have on non-hepatic proteins?

Cortisol causes the degradation of non-hepatic proteins, a decrease of non-hepatic amino acids and a corresponding increase in liver and plasma proteins and amino acids.

What effect does Cortisol have on adipose tissue?

Cortisol degrades adipose tissue to fatty acids to be used for cellular energy, thus cortisol causes a moderate decrease in the use of glucose by the cells.

How alleles of genes on the same chromosomes are inherited together depends on the extent of ____ ____ and ____.

Crossing over and linkage

When does crossing over occur and what does it provide for the organism?

Crossing over occurs in prophase I and it provides another level of genetic recombination.

____ T cells bind to an antigen-carrying cell and release perforin to puncture and lyse the infected cell.

Cytotoxic T cells

What is a mnemonic for the taxonomical system?

Damn King Philip Cuts Open Five Green Snakes

Insulin shock is due to ?

Dangerously low blood glucose levels

What is anemia?

Decreased red blood cell count

What is a protein called when its conformation is disrupted?

Denatured: a denatured protein has lost most of its secondary, tertiary and quaternary structure.

What are the dense bodies found in smooth muscle cells?

Dense bodies in smooth muscle cells are electron-dense portions of smooth muscle which thin filaments (actin and tropomyosin namely) bind to.

What is the Haldane Effect?

Deoxygenation of the blood increases its ability to carry carbon dioxide; this property is the Haldane effect. Conversely, oxygenated blood has a reduced capacity for carbon dioxide.

_______ join two cells at a single point.

Desmosomes: - they attach directly to the cytoskeleton of each cell - hold cells together, but do not prevent fluid from circulating around the sides. - provide tension resistance to a layer of cells. - found in tissues that normally experience a lot of stress, like skin or intestinal epithelium. In other words, they distribute the mechanical force across a tissue. - Desmosomes often accompany tight junctions

What is the process called by which both monocytes and neutrophils enter the damaged or infected tissues?

Diapedesis

_____ is "minimum pressure" in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles (and atria) are filling with blood.

Diastolic pressure.

What is the specialization that occurs at the end of development, forming a specialized tissue cell called?

Differentiation: - the fate of a cell is typically determined early on, but that same cell usually doesn't differentiate into a specialized tissue cell until much later at the end of the developmental process. - * recent research has shown that the fate of even a fully differentiated cell can be altered given the proper conditions.

What is a Dihybrid cross?

Dihybrid cross is the cross of two individuals, each a heterozygote at 2 different genes. - a dihybrid cross is a cross between F1 offspring (first-generation offspring) of two individuals that differ in two traits of particular interest. - A dihybrid cross is often used to test for dominant and recessive genes in two separate characteristics. Such a cross has a variety of uses in Mendelian genetics. - Meiosis (cell reduction) is the cellular process of gamete creation. It is where sperm and eggs get the unique set of genetic information that will be used in the development and growth of the offspring of the mating. The rules of meiosis, as they apply to the dihybrid, are codified in Mendel's First Law and Mendel's Second Law, which are also called the Law of Segregation and the Law of Independent Assortment, respectively.

The hypothalamus synthesizes and releases both ____ and ____ peptide hormones?

Direct and tropic

Out of all 6 anterior pituitary peptide hormones which 2 are direct and which 4 are tropic?

Direct: hGH, PRL Tropic: ACTH, TSH, FSH, LH

Where is the hypothalamus located?

Directly above the pituitary gland

____ evolution exists when two or more species evolving from the same group maintain a similar structure from the common ancestor, called a homologous structure.

Divergent Evolution

What is the Taxonomy of Homo sapiens?

Domain Eukarya Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Mammalia Order Primata Family Homididae Genus Homo Species Sapiens

What are the new super kingdoms called?

Domains: Bacteria, Archaea, Eukarya Archaea is more closely related to Eukarya than is Bacteria.

Why is it that heart and liver cells can produce more ATP for each molecule of glucose than other cells in the body?

Due to a more efficient mechanism for moving NADH produced in glycolysis into the mitochondrial matrix, where this costs an ATP in most other cells.

Why would there be an excess amount of nitrogen found in the urine of a person who has been fasting?

Due to the breakdown of body proteins.

Why would sudden vasodilation occur in flush skin just prior to frostbite in extreme cold?

Due to the paralysis of smooth muscle in the vascular walls.

Explain what happens to the sarcomere and its filaments as contraction occurs:

During contraction, myosin filaments force actin filaments to move closer to each other, pulling the Z bands closer together. - the H zone gets shorter as contraction occurs, because the H zone is the distance between adjacent actin filaments within the same sarcomere - the I band also gets shorter because this is the distance between actin filaments of adjacent sarcomeres. - The A band remains the same length because it is the length of the myosin filaments of a single sarcomere.

What is formed during Gastrulation?

During gastrulation, the 3 primary germ layers are formed: 1) the ectoderm 2) the mesoderm 3) the endoderm

What happens to the diaphragm during inhalation?

During inhalation, the diaphragm contracts and flattens, coming down from its dome-shape, and the external intercostal muscles contract (pushing the rib cage up and out): this increases the volume of the thoracic cavity while reducing the pressure inside the lungs, causing them to fill with air due to the atm pressure. (Negative pressure breathing)

What type of bacteria is found in the large intestine and what is its role?

E.Coli is found in the large intestine. - E. Coli produces vitamin K, B₁₂, thiamin, and riboflavin. - this is a mutualistic symbiosis

What gives the ER its granular appearance?

ER near the nucleus has many ribosomes attached to it on its cytosolic side, giving it a granular appearance, hence the name granular or rough ER.

What surrounds the bronchioles of the lungs?

Each bronchiole is surrounded by a cluster of small air sacs called alveoli within which gas exchange occurs - Bronchioles are also wrapped in smooth muscle

According to the Law of Segregation, which gametic and thus offspring genotype is most likely?

Each gametic genotype is equally likely, thus each offspring genotype is also equally likely.

Describe the multi-unit smooth muscle cells:

Each multi-unit smooth muscle fibre is attached directly to a neuron - a group of multi-unit fibres can contract independently of other muscle fibres in the same location - Multi-unit smooth muscle is found in the large arteries, bronchioles, pili muscles attached to hair follicles, and the iris. - basically, each muscle fibre is innervated by a different neuron, allowing the contraction of single muscle fibres at different times.

What surround its myofibril and for which purpose?

Each myofibril is surrounded by the specialized endoplasmic reticulum of the muscle cell called the sarcoplasmic reticulum: - the lumen of the sarcoplasmic reticulum is filled with Ca²⁺ ions -is smooth ER found in smooth and striated muscle. The only structural difference between this organelle and the smooth ER is the medley of proteins they have, both bound to their membranes and drifting within the confines of their lumens. This fundamental difference is indicative of their functions: The ER synthesizes molecules, while the SR stores and pumps calcium ions. The SR contains large stores of calcium, which it sequesters and then releases when the muscle cell is stimulated.[11] It plays a major role in excitation-contraction coupling.

______ synapses are composed of gap junctions between cells. Cardiac muscle, visceral smooth muscle, and very few neurons in the CNS contains these synapses. Since these synapses do not involve diffusion of chemical messengers, they transmit signals much faster than chemical synapses in both directions.

Electrical Synapses

______ synapses are uncommon, while _____ synapses are the most common.

Electrical; chemical

What are the only 3 forces on the MCAT?

Electromagnetic and Gravitational and Contact

What mechanism is there in the body to inhibit further secretion of endocrine hormones by their glands?

Endocrine glands tend to over secrete their hormones. Some aspect of their effect on the target tissue will inhibit this secretion. - This is Negative Feedback - The control point for negative feedback in endocrine glands is the conduct of the effector, not the concentration of the hormone. - The gland lags behind the effector - For instance, high insulin levels do not create low blood glucose, instead, high insulin levels are caused by high blood glucose, and low blood glucose would cause high blood glucagon levels. It is expected that there will be high levels of the hormone that is responding to the condition.

The euk cell contains a thick maze of membranous walls called the _____ ______ separating the cytosol for the lumen of the ____ ______ or cisternal space.

Endoplasmic reticulum; ER. - In many places, the ER is contiguous with the cell membrane and the nuclear membrane. The ER lumen is contiguous in places with the space between the double bilayer of the nuclear envelope.

What is the 7th type of peptide hormone and what is its function?

Endorphins/Enkephalins: - these act as direct hormones to inhibit the perception of pain.

Some gram positive bacteria can form ______ that can lie dormant for hundreds of years. They are resistant to heat, UV, chemical disinfectants, and desiccation.

Endospores: - can survive boiling water for over an hour

According to the ____ _____, mitochondria may have evolved from a symbiotic relationship between ancient proks and euks.

Endosymbiont theory

Simple epithelium is one layer thick while stratified epithelium is two or more layer thick. Simple epithelium includes _______ lining the various vessels of the body including the heart.

Endothelium

Vmax is proportional to what?

Enzyme concentration

What happens to the enzyme during the reaction?

Enzymes are not consumed nor permanently altered by the reactions which they catalyze.

What role do Eosinophils play?

Eosinophils work mainly against parasitic infections

______ ___ are epithelial cells that line the space containing the CSF. They use cilia to circulate the CSF.

Ependymal Cells: - line the cavities of the CNS and make up the walls of the ventricles. These cells create and secrete cerebrospinal fluid(CSF) and beat their cilia to help circulate the CSF and make up the Blood-CSF barrier. They are also thought to act as neural stem cells.

_____ is a powerful vasoconstrictor causing arteries to narrow

Epinephrine

How do the other tyrosine derivative hormones, epinephrine and norepinephrine, exert their effects on the effector?

Epinephrine and norepinephrine are water soluble, thus they dissolve in and travel freely through the blood. - They bind to receptors on the target tissue and act mainly through the second messenger cAMP.

The NT used by the post-ganglionic neurons of the sympathetic nervous system is either?

Epinephrine or norepinephrine (also called adrenaline and noradrenaline); they are adrenergic

What is an Episome?

Episomes are the eukaryotic equivalent of bacterial plasmids. In general, in eukaryotes, episomes are closed circular DNA molecules that are replicated in the nucleus.

What do the myeloid stem cells divide into?

Erythrocytes, platelets, monocytes, neutrophils, eosinophils, basophils

What is the purpose of estradiol?

Estradiol prepares the uterine wall for pregnancy.

What is the difference between Prok and Euk flagella?

Euk flagella is composed of the 9+2 arrangement of tubulin filaments, whereas prok flagella is composed if a single strand of the protein flagellin. - Euk flagella undergo whip-like motion whereas Prok flagella rotate.

When did the Eukaryotes evolve?

Eukaryotes evolved around 1.5 billion years ago, and did not develop into multicellular organisms until several million years later.

Why is it a problem when animals act as carrier populations for viruses?

Even if all viral infections of a certain type were eliminated in humans, the virus may continue to thrive in another animal, maintaining the ability to reinfect the human population

______ is a change in the gene pool.

Evolution: - Even if the ratio of blue eyed to brown eyed individuals temporarily changes, as long as the gene pool remains the same in terms of alleles ratios, the population has not evolved.

_____ ____ is when a species faces a crisis so severe as to cause a shift in the allelic frequencies of the survivors of the crisis.

Evolutionary Bottleneck

Most tissues are drained by lymphatic channels except what?

Except the central nervous system.

Some NTs are capable of ______ or _____ depending on upon the type of receptor in the post-synaptic membrane. Acetylcholine, for example has an _____ effect on the heart, but and ______ effect on the visceral smooth muscle of the intestines.

Excitation or inhibiton; - Acetylcholine, for example has an inhibitory effect on the heart, but and excitatory effect on the visceral smooth muscle of the intestines. - Acetylcholine, inhibits heart rate, and excites the digestive system when the parasympathetic NS is triggered.... ParaNS= rest and digest.

Describe the oxygen dissociation curve for exercising muscle:

Exercising muscle would have a great right shifted curve, as more H⁺ ions, Heat and CO₂ would be produced... thus, facilitating more oxygen unloading into the tissue by Hb.

During _____, the diaphragm relaxes back to its dome-shaped position.

Exhalation - rib cage gets smaller as external intercostal rib muscles relax

Is exhalation passive or forced?

Exhalation is passive as the lungs and chest are highly elastic and tend to recoil to their original position once the diaphragm is relaxed.

The pancreas not only increases the pH of the duodenum via bicarbonate ion but it also acts as an _____ gland.

Exocrine Gland by releasing enzymes from its acinar cells through the pancreatic duct into the duodenum.

What type of glands exist in the stomach and where are they located?

Exocrine glands located in the gastric pits of the stomach

_____ glands release enzymes to the external environment through ducts; where as ______ glands release hormones directly into body fluids.

Exocrine; endocrine

_________ is the durable process by which a cell directs the contents of secretory vesicles out of the cell membrane and into the extracellular space. These membrane-bound vesicles contain soluble proteins to be secreted to the extracellular environment, as well as membrane proteins and lipids that are sent to become components of the cell membrane.

Exocytosis

_______ refers to the degree to which a particular phenotype expresses itself in the genotype.

Expressivity: - for example, the severity of a disease can differ between two people with the same disease genotype.

What do FSH and LH do during the proliferative/follicular phase?

FSH and LH from the anterior pituitary gland act together to promote the development and growth of several ovarian follicles.

When does FSH peak?

FSH peaks right before ovulation

What does FSH cause in males?

FSH stimulates the Sertoli cells of the testes to surround and nurture the spermatids and spermatocytes. It also acts to stimulate the sertoli cells to secret inhibin which acts to inhibit further FSH secretion

What are the 4 hormones that regulates the menstrual cycle?

FSH, LH, Estrogen and Progesterone.

What are the only non-steroidal reproductive hormones?

FSH, LH, HCG and inhibin, which are all peptides.

What are the hormones of the Anterior Pituitary?

FSH; Follicle stimulating hormone LH; Leutinizing Hormone ACTH; Adrenocorticotropic Hormone HGH; Human growth hormone TSH; Thyroid-stimulating hormone Prolactin

In what form do most fats reach the cell?

Fatty Acids

How do fatty acids/triglycerides enter the krebs cycle?

Fatty acids are brought into the intermembrane space and converted to acyl CoA via ATP hydrolysis. The Acyl CoA then diffuses into the mitochondrial matrix where it is converted into Acetyl CoA... then enters the Krebs cycle. Triglycerides can be catabolized for ATP. Fatty acids are converted to acyl coa along the outer membrane of the mitochondria and the endoplasmic reticulum at the expense of one ATP.

Where does fertilization normally take place?

Fertilization normally takes place within the fallopian tubes.

When exactly does fertilization occur?

Fertilization occurs when the nuclei of the ovum and sperm fuse to form the diploid zygote

How is the curve for Fetal Hb compared to that for adult Hb?

Fetal Hb has a higher affinity for O₂ than adult Hb, thus it has a left-shifted curve compared to adult Hb, because of a reduced affinity for 2,3-BPG/DPG

Where are the fibroblasts located and what is their purpose?

Fibroblasts are located in the dermis, they make fiber and ground substances for the ECM that holds this connective tissue together.

Specialized cells called _______ secrete fibrous proteins such as elastin and collagen that form a molecular network that holds tissue cells in place called an _____ _______.

Fibroblasts; Extracellular Matrix. - the consistency of the matrix may be in the form of liquid as in blood, or solid as in bone.

_____ joints hold two bones tightly together with ____ tissue, allowing for little movement, as in the skull.

Fibrous joints hold two bones tightly together with fibrous tissue, allowing for little movement. - Skull bones form fibrous joints with each other, and the teeth form fibrous joints with the mandible.

Fight or flight is _______; while rest and digest is ______?

Fight or flight is Sympathetic; while rest and digest is Parasympathetic

An afferent arteriole in a glomerular tuft contains microscopic fenestrations which increase fluid flow. In a hypertensive patient (high blood pressure), what would be expected of filtrate volume?

Filtrate volume would be larger due to greater fluid/hydrostatic pressure.

What part of the brain is involved in inspiration of air?

Inspiration of air occurs when the medulla oblongata of the midbrain signals the diaphragm to contract.

Which hormone inhibits glycogenolysis?

Insulin

______, a peptide hormone, is released by the β-cells of the pancreas. It is associated with energy abundance in the form of high energy nutrients in the blood.

Insulin

How does insulin illicit its effect in cells?

Insulin binds to a membrane receptor thus starting a cascade of reactions inside the cell. This causes the cells of the body (except for neurons in the brain) to become highly permeable to glucose. - The permeability to amino acids is also increased. - Intracellular metabolic enzymes are activated and even transcription and translation rates are affected.

What effect does insulin have on the diffusion of glucose?

Insulin increases the rate of facilitated diffusion for glucose and other monosaccharides.

What stimulates the release of Insulin from the β-cells of the pancreas?

Insulin is released when blood levels of carbohydrates or proteins are high. It affects proteins, fat and carbohydrate metabolism.

What type of membrane proteins, found in the membrane of a neuron, contribute to depolarization?

Integral membrane proteins called voltage gates sodium channels.

What are the proteins called that transverse the membrane from the outside of the cell to the inside of the cell?

Integral or Intrinsic proteins and they are amphipathic

Mating relatives is called _____, and does not change the frequency of alleles, but does increase the number of homozygous individuals within a population.

Interbreeding

What role do the intercostal muscles play?

Intercostal muscles or those muscles between the ribs also help to expand the chest cavity while breathing.

_______ lipoproteins and _____ lipoproteins transport cholesterol and phospholipids to the cells of the body.

Intermediate and LDL

____ ______ are stronger than actin filaments and function in maintaining cell shape. They can be composed of vimentins (cell structura support), keratin (skin cells), or lamin (nuclear envelope).

Intermediate filaments.

_______ transfer signals from neuron to neuron.

Interneurons; 90% of neurons in the human body are interneurons

Describe the path air takes from the mouth/nose:

Into the mouth or nasal passages→through the throat /pharynx→passed the epiglottis→into trachea→into left and right bronchi→bronchioles→alveoli

What role does myoglobin play?

It allows O₂ to be stored in muscles for long periods of time. It has an instant binding affinity for oxygen and is found only in muscle tissue to allow for immediate release of oxygen when needed.

What role does the nasal cavity play in breathing?

It filters, moistens and warms incoming air. - coarse hair at the front of the cavity traps large dust particles - mucous secreted by goblet cells traps smaller dust particles and moistens the air - capillaries within the nasal cavity also warm the air

What happens to the osmolarity of the filtrate as it moves from the bottom of the loop to the top of the ascending loop of Henle?

It goes from an osmolarity of 1200 to 100 because so much salt is removed from the filtrate during the ascent.

What does the lower brain do?

It integrates subconscious activities such as the respiratory system, arterial pressure, salivation, emotions, and reaction to pain and pleasure.

What is Myoglobin?

It is an oxygen binding molecule that consists of a single polypeptide chain and has only one heme group which binds to only one O₂ molecules. - It does not exhibit cooperative binding because it only has one heme group

What is the opening to the archenteron in the gastrula called, and what will it later develop into?

It is called the blastopore and it will later develop into the anus.

Where is carbon dioxide partial pressure greatest?

It is greatest in the blood in the systemic capillary beds than in the alveoli of the lungs... this allows CO₂ to travel from highest pressure to lowest pressure, and thus into the alveoli of the lungs from the capillary beds, to be exhaled.

What happens to the remaining portion of the follicle that is left behind in the ovary?

It is left behind to become the corpus luteum.

What happens to the secondary oocyte once released from the ovary?

It is released into the abdominal cavity, swept into the fallopian tubes via the fallopian fimbriae. The follicle which expelled the secondary oocyte now becomes the corpus luteum. - the secondary oocyte then waits in the fallopian tubes for 24 hours until fertilization by a sperm cell.

What happens to NAD+ in fermentation?

It is restored for use in its role in glycolysis as a coenzyme, and the lactic acid or ethanol is expelled from the cell along with carbon dioxide as a waste product.

What then happens to the blastocyst?

It is the blastocyst that lodges into the uterus in a process called implantation on about the 5th to 7th day after ovulation.

What is substrate level phosphorylation and at which two steps in glycolysis does it occur?

It is the formation of ATP from ADP and one inorganic phosphate group using the energy released from the decay of high energy phosphorylated compounds as opposed to using energy from diffusion. It occurs at step 6 via phosphoglycerate kinase and at step 9 via pyruvate kinase

When one of a pair of antagonistic muscles contracts, what usually happens to the other muscle to produce movement?

It relaxes to allow movement

What effect does ADH have on the filtrate of the distal tubule?

It removes water from the filtrate, concentrating the filtrate.

What is hypovolemic shock and when is it most likely to occur?

It represents a set of symptoms that occur when a patient's blood volume drops abruptly and is most likely to occur via arterial bleeding.

What effect does 2,3-BPG or 2,3-DPG have on the Oxygen Dissociation curve and why?

It shifts the curve to the right by binding to partially deoxygenated Hb to facilitate complete O₂ unloading

What are the main components involved in the coagulation process?

It starts with platelets and includes the plasma proteins prothrombin→thrombin via prothrombin activator enzyme, and fibrinogen→fibrin via thrombin

What does exposure to friction or pressure stimulate the epidermis to do?

It stimulates the epidermis to thicken forming a callus.

How does the body keep the body warm via the skin?

It will shunt blood away from the capillaries of the skin to reduce heat loss, keeping the body warm.

Would it be better to rest or exercise following a meal? Explain:

It would be better to rest because activation of the sympathetic NS via exercise increases vasodilation of blood vessels to the active muscle tissue and vasoconstriction of blood vessels to digestive organs.

What happens to the estradiol levels just before ovulation (bursting of the follicle) and what does this cause?

Just before ovulation, the estradiol levels rise rapidly, actually causing a dramatic increase in LH secretion. This is called the Luteal Surge

__-selected species put their energy into ensuring their offspring survive.

K-selected - in stable or predictable environments, K-selection predominates as the ability to compete successfully for limited resources is crucial - close to the maximum that the environment can bear - large body size, long life expectancy, fewer offspring and require extensive parental care until maturity

___ - selection involves small brood(family of young animals) size with slow maturing offspring and strong parental care.

K-selection: - K-strategists have a sigmoidal growth curve which levels off at the carrying capacity. - the carrying capacity is the maximum number of organisms that an environment can maintain.

What is produced when the liver mobilizes fat for energy production?

Ketone Bodies, which often results in ketosis or acidosis. - when the liver uses fat or protein for energy production, the blood acidity increase/ pH decreases.

What are the types of T-Cells?

Killer T cells also called cytotoxic T cells Helper T cells Memory T cells Suppressor T cells

Which type of T cell is responsible for fighting forms of cancer and for attacking transplanted tissue?

Killer/Cytotoxic T cells

_______ walks along the microtubule towards the + end?

Kinesin

What is the taxonomic classification system?

Kingdom Phylum Class Order Family Genus Species

What are the phagocytotic cells of the liver calles?

Kupfer cells

When does LH peak?

LH peaks immediately prior to ovulation

What does LH cause in males?

LH stimulates the leydig cells of the testes to produce and release testosterone.

What triggers endospores formation?

Lack of nutrients.

What is the area in which an osteocyte resides called?

Lacuna

Type I slow twitch muscle fibres contain large amounts of _____ for what reason?

Large amounts of mitochondria - they are slow to fatigue but also have a slow contraction velocity because they split ATP at a slow rate. - Type I slow twitch muscle fibres are resistant to fatigue.

Why are large arteries less affected by sympathetic innervation?

Large arteries have less smooth muscle per unit volume than medium arteries, and are thus less affected by sympathetic innervation.

What is the period from infection of a host cell to lysis called?

Latent period; which encompasses the eclipse period.

What is Mendel's second Law of Heredity and what does it state?

Law of Independent Assortment: - states that genes located on different chromosomes assort independently of each other. - That is, the biological selection of a particular gene in the gene pair for one trait to be passed to the offspring has nothing to do with the selection of the gene for any other trait. More precisely, the law states that alleles of different genes assort independently of one another during gamete formation. - In other words, genes that codes for different traits, when located on different chromosomes, do not affect each other during gamete formation. - If two genes are located on the same chromosome, the likelihood that they will remain together during gamete formation is indirectly proportional to the distance separating them. -Mendel performed dihybrid crosses in plants that were true-breeding for two traits. For example, a plant that had green pod color and yellow seed color was cross-pollinated with a plant that had yellow pod color and green seeds. In this cross, the traits for green pod color (GG) and yellow seed color (YY) are dominant. Yellow pod color (gg) and green seed color (yy) are recessive. The resulting offspring or F1 generation were all heterozygous for green pod color and yellow seeds (GgYy). - Along with crossing over, independent assortment increases genetic diversity by producing novel genetic combinations. - In metaphase I of meiosis, homologous chromosomes align independently of one another along the metaphase plate

What is Mendel's first law of heredity and what does it state?

Law of Segregation: - states that alleles segregate independently of each other when forming gametes. Any gamete is equally likely to possess any allele. - also, the phenotypic expression of the alleles is not a blend of the two, but an expression of the dominant allele (the principle of complete dominance). - states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization. - this occurs during separation of homologous pairs in meiosis I - a gamete will receive only one allele during gamete formation - a zygote will receive two alleles, one from each parent.

Why does small intestine length increase from 3 m to 6 m in a cadaver?

Length increases when a person dies because of the loss of the smooth muscle tone.

Upon contraction, the smooth muscle cell shrinks ____-wise.

Length-wise

What do the Leydig cells do?

Leydig cells of the testes, located in the interstitium between the tubules, release testosterone when stimulated by LH. - also called interstitial cells

____ connect bone to bone

Ligaments

What does a ligase do?

Ligases govern an addition reaction, but require energy from ATP or some other nucleotide. Ligases are sometimes called synthetases.

Do enzymes alter the equilibrium of a reaction?

Like any catalyst, enzymes do not alter the equilibrium of a reaction.

_____ degrades fat, specifically triglycerides.

Lipase degrades fat into fatty acids and monoglycerides via lipid hydrolysis. - hydrolyzes emulsified lipids (formed from bile) and converted to active form by trypsin.

What are the 4 most important pancreatic enzymes?

Lipase, pancreatic amylase, trypsin and chymotrypsin

What enzymes degraded lipids/fats?

Lipase, with the help of bile.

Where does fat digestion begin?

Lipid or fat digestion begins in the small intestine/duodenum.

Since Lipids are insoluble in aqueous solution, how are they transported in the blood without aggregating in the blood?

Lipids are transported in the blood via lipoproteins. A lipoprotein contains a lipid core surrounded by phospholipids and apoproteins, thus the lipoprotein is able to dissolve lipids in its hydrophobic core and then move freely through the aqueous solution due to its hydrophilic shell.

Lipids:

Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E, and K), monoglycerides, diglycerides, triglycerides, phospholipids, and others. The main biological functions of lipids include energy storage, as structural components of cell membranes, and as important signaling molecules. Any molecule that has low solubility in water and high solubility in non-polar organic solvents.

What are most microorganisms capable of doing?

Fixing CO₂: reducing it and using the carbon to create the organic molecules needed

______ have a wiggle action causing the fluid to move away from the cell.

Flagella

In which types of bone is red marrow found?

Flat bones and in the cancellous (spongy) material at the epiphyseal ends of long bones

Describe the shape and composition of flat bones:

Flat bones are made from spongy bone surrounded by compact bone. They provide large areas for muscle attachment, and organ protection. - The skull, sternum, ribs and shoulder blades are flat bones

What does it mean that the lymph system is an open system?

Fluid enters at one end and leaves at the other end. Lymph capillaries are like tiny fingers protruding into tissues. - to enter the lymph system, interstitial fluid flows between overlapping endothelial cells. - large particles literally push their way between the cells into the lymph - the cells overlap in such a fashion that once inside, large particles cannot push their way out.

What is the Normal Force ALWAYS equal to for an inclined plane?

Fn=mgcosθ

What are the force due to gravity and the normal force of an inclined plane ALWAYS equal to for any point directly along the plane?

Fnet=mgsinθ=Fnsinθ Fn=Fg=mg mgsinθ is the vector sum of the weight and the normal force.

_____ ______ hormone is an anterior pituitary tropic peptide hormone that causes maturation of ovarian follicles in females and stimulates the maturation of the seminiferous tubules for sperm production in males.

Follicle Stimulating Hormone; FSH

What are the 2 things that can activate B lymphocytes?

Free antigens or Helper T-cells

What are the different types of cells involved in and beneath the retina?

From Top to Bottom: Rod and Cones cells Horizontal cells Bipolar cells Amacrine cells Ganglion cells--> optic nerve fibres

What happens to oxygen from each alveolus?

From each alveolus oxygen diffuses into a capillary where it is picked up by red blood cells. - these red blood cells release carbon dioxide, which diffuses into the alveolus, and is expelled upon exhalation.

How do fats or fatty acids travel through the blood?

From the adipose tissue, most fatty acids are transported in the form of free fatty acids, which combines immediately in the blood with albumin. - A single albumin molecule typically carries 3 fatty acids but may carry up to 30.

Where does light go from the anterior cavity?

From the anterior cavity, light passes through the pupil, a hole in the centre of the eye created by the Iris, and enters the lens.

From which capillary bed does the liver receive blood?

From the capillary beds of the intestines, stomach, spleen, and pancreas all via the Hepatic Portal Vein.

Describe the path of the concentrated urine from the collecting Duct.

From the collecting ducts → renal calyx→renal pelvis→ureter→bladder→urethra for expulsion

Where does light go from the cornea?

From the cornea, light enters the anterior cavity which holds the aqueous humor. - Aqueous humor is formed by the ciliary processes and leaks out the canal of Schlemm.

Where does the filtrate go from the Proximal Tubule?

From the proximal tubule, the filtrate flows into the descending loop of Henle. - The loop of Henle dips into the medulla of the kidney

How is fructose absorbed?

Fructose is absorbed via facilitated diffusion (GLUT5), and much of it is converted to glucose while inside the enterocyte.

All ____ are eukaryotic heteroautotrophs.

Fungi

____ cells secrete gastrin into the interstitium.

G cells

What are small populations subject to?

Genetic drift where one allele may be permanently lost due to the death of all members having that allele. Genetic drift is not caused by selective pressure, so its results are random in evolutionary terms.

Nervous tissues contain many support cells called ___ _____ or _____.

Glial cells or neuroglia: - are non-neuronal cells that maintain homeostasis, form myelin, and provide support and protection for neurons in the brain, and for neurons in other parts of the nervous system such as in the autonomic nervous system

_______ are a group of proteins that contain antibodies. Most ______ are made in the liver, however, antibodies are not, they are made by plasma cells.

Globulins

Outline the components of the Nephron from start to end:

Glomerulus-Bowman's Capsule- Proximal Convoluted tubule- ThickmDescending Loop of Henle- Thin descending loop of Henle- Thin Ascending loop of Henle- Thick ascending loop of Henle- Distal Convoluted Tubule- Collecting Duct

How does glucagon illicit a response in cells?

Glucagon acts via the second messenger system of cAMP.

Glucagon stimulates _______ (breakdown of glycogen), and ________ in the liver.

Glucagon stimulates glycogenolysis (breakdown of glycogen), and gluconeogenesis (formation of glucose) in the liver.

_____, a peptide hormone, released by the α-cells of the pancreas, increases blood glucose levels by stimulating protein and fat degradation, conversion of glycogen to glucose and activation of gluconeogenesis.

Glucagon.

________ increase blood glucose concentration and have an even greater effect on fat and protein metabolism.

Glucocorticoids

________ are steroid-based hormones, they increase blood glucose by promoting gluconeogenesis, decreasing protein synthesis, and decreasing the immunological/inflammatory response.

Glucocorticoids, the main one being cortisol - gluconeogenesis is the creation of glucose and glycogen, mainly in the liver, from amino acids, glycerol, and lactic acid.

What hormones are produced in the adrenal cortex?

Glucocorticoids: Cortisol Mineral Corticoids: Aldosterone

What does it mean when there is glucose found in the patient's urine?

Glucose influx into the filtrate is occurring faster than it can be reabsorbed. - Glucose is normally completely reabsorbed from the filtrate and thus should not appear in the urine. - When glucose appears in the urine, the glucose transporters in the Proximal Convoluted Tubule, are unable to reabsorb all the glucose from the filtrate.

How is glucose absorbed into the enterocytes of the small intestine?

Glucose is absorbed by a secondary active transport mechanism down the concentration gradient of sodium. - sodium is actively pumped out of the enterocyte on the basolateral (blood) side, while potassium is pumped in. The resulting low sodium concentration inside the enterocyte drags sodium from the intestinal lumen into the cell through a transport protein at the apical side, but only after glucose has also attached itself to the protein. - Thus, glucose is dragged into the enterocyte by sodium.

Where did early organisms initially assimilate carbon from?

Methane and Carbon dioxide from the early atmosphere

What is the 6 carbon carbohydrate called?

Glucose, the most commonly occurring six carbon carbohydrate. 80% of the carbohydrates absorbed by humans

80%% of the end product of carbohydrate digestion is ______ and 95% of the carbohydrates in the blood are _____?

Glucose: Glucose

What are the 9 non-polar amino acids?

Glycine, Valine, Leucine, Isoleucine, alanine, phenylalanine, tryptophan, methionine and proline

The ______ separates the cell membrane from the ECM, though it is made from the same material as the matrix so it is difficult to identify.

Glycocalyx: is involved in cell-cell recognition, adhesion, cell surface protection and permeability

The formation of glycogen is called?

Glycogenesis

_________ are similar to phospholipids, except they have one or more carbohydrates attached to the three-carbon glycerol backbone instead of the phosphate group.

Glycolipids, which are also amphipathic

How are Hydrogen ions secreted into the filtrate?

H ions are secreted into the filtrate through the Proximal cells via an antiport system with sodium, which is driven by the sodium concentration gradient. - In this system, the proton crosses the membrane in the opposite direction to sodium.

What is the first outward sign of pregnancy?

HCG in the blood and urine of a woman.

In which direction does Carbonic Anhydrase function in the lungs?

HCO⁻₃ + H⁺ → H₂CO₃ →(via carbonic anhydrase) CO₂ + H₂O - thus, in the lungs carbonic anhydrase creates H₂O and CO₂, which are then expelled - this effectively lowers blood H⁺ concentration and increases pH.

Parietal Cells secrete:

HCl due to stimulation via the releases of gastrin into the blood from G Cells.

Why is HDL called "good cholesterol"?

HDL particles are able to remove cholesterol from within artery atheroma and transport it back to the liver for excretion or re-utilization, which is the main reason why the cholesterol carried within HDL particles (HDL-C) is sometimes called "good cholesterol"

HIV attacks which cells of the immune system?

HIV attacks the Helper T cells of the Cell-mediated immune system

How is hair on the skin involved in keeping the body warm?

Hair can be erected (piloerection) via sympathetic stimulation trapping insulating hair next to the skin.

What is hair?

Hair is a column of keratinized cells held tightly together. as new cells are added to its base, the hair grows. - most hairs are associated with a sebaceous (oil) gland that empties oil directly into the follicle and onto the skin. - when contracted, smooth muscle (arrector pili), also associated with each hair, stands hair up pointing it perpendicular to the skin.

What is the selective advantage offered by the haploid state of fungi?

Haploid spores can form and spread faster and more efficiently than diploid zygotes because they do not undergo meiosis. The haploid state can reproduce more quickly under favorable conditions.

How can Haptens stimulate an immune response?

Haptens can only stimulate an immune response if the body had previously been exposed to the full antigen.

Hardening of the arteries seems to be induced by the ______ density lipoproteins, but impeded by ______ density lipoproteins.

Hardening of the arteries seems to be induced by the low density lipoproteins, but impeded by high density lipoproteins. Therefore, HDL is good, LDL is bad. - Total fat-intake also plays a role in blood-cholesterol levels. This effect is thought[by whom?] to come about by changes in the quantity of cholesterol and lipoproteins that are synthesized by the body. In particular, saturated, monounsaturated and polyunsaturated fats have been shown to increase HDL-based cholesterol levels, with saturated fats also increasing LDL-based cholesterol levels. Trans fats have been shown to reduce levels of HDL whilst increasing levels of LDL. Based on such evidence and evidence implicating low HDL and high LDL levels in cardiovascular disease (see Hypercholesterolemia), many health authorities advocate reducing LDL cholesterol through changes in diet in addition to other lifestyle modifications. The USDA for example recommends that those wishing to reduce their cholesterol through a change in diet should aim to consume less than 7% of their daily energy needs from saturated fat and fewer than 200 mg of cholesterol per day. An alternative view is that any reduction to dietary cholesterol intake could be counteracted by the organs compensating to try to keep blood cholesterol levels constant. - LDL is bad: HDL is good

A population with the five characteristics posited by Hardy and Weinberg is said to be in?

Hardy-Weinbergy Equilibrium - no real population ever possesses these characteristics completely.

_____ canals contain lymph and blood vessels which are cross-linked by Volkmann's Canals.

Haversian

Hydrophilic:

Having an affinity for water; readily absorbing or dissolving in water. A hydrophilic molecule or portion of a molecule is one that is typically charge-polarized and capable of hydrogen bonding, enabling it to dissolve more readily in water than in oil or other hydrophobic solvents. Hydrophilic and hydrophobic molecules are also known as polar molecules and nonpolar molecules, respectively.

What type of muscle is heart muscle composed of?

Heart muscle is composed mainly of cardiac muscle.

Pulse is a direct measure of?

Heart rate or beats per minute

____ T cells, the ones attacked by HIV, recognize APC macrophages and activate required B cells and cytotoxic T cells for both humoral and cell-mediated immunity

Helper T cells

Gluconeogensis occurs mainly in which organ?

Liver

One job of the ____ is to maintain a fairly constant blood glucose level of 90mg/dl between meals to 140mg/dl after a meal.

Liver: - the liver absorbs all the carbohydrates and converts all the galactose and fructose into glucose, then into glycogen for storage.

What are the infectious agents that are able to pass through the skin or digestive defences and enter the body first attacked by?

Local Macrophages - these phagocytic giants can engulf as many as 100 bacteria - these macrophages then stimulate the activation of the acquired immunity response.. later on

Describe how the Paracrine System works:

Local mediators are released by a variety of cells into the interstitial fluid, fluid between cells, and act on neighboring cells a few millimeters away. - local mediators may be proteins, amino acid derivatives, or even fatty acids. - prostaglandins, growth factors and lymphokines are all examples of local mediators.

What is located deep between the villi of the small intestine?

Located deep between the villi of the small intestine are the intestinal exocrine glands, the crypts of Lieberkuhn. These glands secrete an interstinal juice with a pH of 7.6 and lysozyme.

Where is the Atrioventricular Node (AV Node) located?

Located directly above the right ventricle in the interatrial septa, the wall of cardiac muscle between the atria

___ is the position of a gene along a chromosome

Locus

Describe the shape and composition of long bones:

Long bones have s shaft that is curved for strength, they are composed of compact and spongy bone. They are arm, leg, finger and toe bones

Smooth muscle contractions are ____ and ____ than skeletal muscle contractions>

Longer and slower

___ ___ ___ concentrates solutes in the medulla

Loop of Henle

If ADH holds water in the in the body, decreasing urine output and increasing blood pressure, does a person with high blood pressure (holding water) have a high ADH blood level or low ADH blood level.

Low ADH because it responded to the body

During sexual reproduction, _____ and ____ are inherited from the mother due to simple dilution factors.

Mitochondria and mtDNA, due to simple dilution factors (an egg contains around 1,000,000 mtDNA molecules, whereas a sperm contains 100-1000). - Mitochondrial DNA is therefore inherited from a single lineage, allowing researchers to determine that all humans descended from East Africa, approximately 200,000 years ago.

What does facilitated diffusion do to the membrane?

Makes the membrane selectively permeable because it is able to select between molecules of similar size and charge

How are lymphocytes created?

Mammalian stem cells differentiate into several kinds of blood cell within the bone marrow.[4] This process is called haematopoiesis. All lymphocytes originate, during this process, from a common lymphoid progenitor before differentiating into their distinct lymphocyte types. The differentiation of lymphocytes follows various pathways in a hierarchical fashion as well as in a more plastic fashion. The formation of lymphocytes is known as lymphopoiesis. - B cells mature into B lymphocytes in the bone marrow, while T cells migrate to and mature in a distinct organ, called the thymus. - Following maturation, the lymphocytes enter the circulation and peripheral lymphoid organs (e.g. the spleen and lymph nodes) where they survey for invading pathogens and/or tumor cells.

Describe how proteolytic cleavage regulates enzymes:

Many enzymes are released into their environment as inactive forms called zymogens or proenzymes. When specific peptide bonds on zymogens are cleaved, the zymogens become irreversibly activated. Pepsinogen (-ogen=zymogen status) is cleaved by low pH to produce the active enzyme pepsin, in the stomach.

What are Mast cells and what do they do?

Mast cell are involved in wound healing, defence against pathogens, and involved in the allergic response. - they also release histamine - they can cause anaphylaxis or anaphylactic shock

How is mitochondrial DNA passed to the offspring?

Maternally, even in organisms whose male gamete-contributes to the cytoplasm.

Where does mechanical digestion begin?

Mechanical digestion begins in the mouth via chewing/mastication. Chewing breaks down the food, resulting in smaller particles which provide greater surface area for enzymes to access at any one time.

____ arteries constrict enough under sympathetic stimulation to reroute blood.

Medium

What are the components of the lower brain?

Medulla, pons, mesencephalon, hypothalamus, thalamus, cerebellum and basal ganglia.

What happens to the Memory B cells after the infection is taken care of?

Memory B cells will proliferate and remain in the body - In the case of re-infection, each of these cells can be called upon to synthesize antibodies, resulting in a faster acting and more potent affect called the Secondary response.

____ T cells function the same as ____ B cells. They stay in the bloodstream to elicit more immediate and potent immune responses upon secondary infection.

Memory T cells

What is Mendelian Genetics?

Mendelian genetics is a set of primary tenets relating to the transmission of hereditary characteristics from parent organisms to their offspring.

How does menopause contribute to osteoporosis?

Menopause reduces estrogen levels leading to diminished osteoblast activity.

What is the structure of the mitochondrion?

Mitochondria are surrounded by two phospholipid bilayers. The inner membrane invaginates to form the cristae. It is the inner membrane that holds the ETC - Between the inner and outer membrane is the intermembrane space.

Like prokaryotes, mitochondria have their own ______ DNA that replicates independently from the euk cell.

Mitochondria have circular DNA like proks. - This DNA has no histones or nucleosomes. - most animals have a few dozen to several hundred molecules of circular DNA in each mitochondrion.

Which organelle is abundant in parietal cells?

Mitochondria, because a lot of energy is needed to manufacture HCl.

The centrosome is also commonly called the?

Mitotic Organizing Center (MTOC)

Describe X-Linked Recessive Inheritance:

Mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males (hemizygous for the gene mutation due to only one X-chromosome) and in females who are homozygous for the gene mutation. - affects mainly males - Affected male (XaY) x unaffected female (AA): boys will be unaffected (XY), girls will be unaffected carriers (XaX). - Affected male(XaY) x carrier female (XaX): boys will be 50% affected (XaY) and 50% unaffected (XY), girls will be 50% affected (XaXa) and 50% unaffected (XaX) - affected male (XaY) x affected female (XaXa): all children will be affected - Unaffected male (XY) x carrier female (XaX): boys will be 50% affected (XaY) and 50% unaffected (XY), girls will be 50% unaffected carriers (XaX) and 50% unaffected (XX). - Unaffected male (XY) x affected female (XaXa): all boys will be affected (XaY), all girls will be carriers (XaX) - there is no male-to-male transmission in the pedigree (but the matings of an affected male with a female carrier can give the appearance of male-to-male transmission) - Examples are red-green colour blindness, hemophilia and muscular dystrophy

What are the agranular leukocytes?

Monocytes, lymphocytes, and megakaryocytes

How do the monoglycerides and fatty acids enter the enterocyte and what happens to them once inside the enterocyte?

Monoglycerides and fatty acids diffuse into the enterocyte and are converted back into triglycerides and then to globules by the SER. - Globules move to the golgi apparatus where they become chylomicrons and undergo exocytosis to the basolateral side.

What is a monohybrid cross and what did Mendel discover using the cross?

Monohybrid Cross is a mating between individuals who have different alleles at one genetic locus of interest. The character(s) being studied in a monohybrid cross are governed by two alleles for a single locus. - monohybrid cross is of only one gene! - the individuals genotype would look like Rr x Rr, for example - Mendel discovered that is was possible to detect genotypic/physiological ratios of progeny from two distinct parents.

In what form is most of the calcium in the body stored?

Most of the Ca²⁺ is stored in the bone matrix as Hydroxyapatite.

In which parts of the small intestine does most of the absorption take place?

Most of the absorption occurs in the jejunum and the ileum.

In which part of the small intestine does most of the digestion take place?

Most of the digestion occurs in the duodenum of the small intestine

What happens to a protein once a denaturing agent has been removed?

Most of the time the protein will refold to its original conformation. Suggesting that the amino acid sequence plays a key role in conformation of a protein.

Where are the old RBCs disposed of?

Most of them burst in the spleen or liver after 120 days

In what condition do most proteins reach the brush border and what happens to them there.

Most proteins reach the brush border as small polypeptides. Here they are reduced to amino acids, dipeptides, and tripeptides before they are absorbed into the enterocytes.

A ____ _____ _____ is a chemical synapse that connects neuron to a muscle.

Motor end plate; is unidirectional... one direction

_____ or _____ neurons carry signals to a muscle or gland called the effector organ.

Motor or efferent;

What is the basic anatomy of the digestive tract?

Mouth, esophagus, cardiac sphincter of the stomach (orifice), stomach, Pyloric Sphincter of the stomach, small intestine (duodenum, ileum, jejunum), Cecum/appendix, large intestine ,(ascending colon, transverse colon, descending colon, sigmoid colon), rectum and anus.

What happens to the bile after it is used in the small intestine?

Much of the bile is reabsorbed by the small intestine and transported back to the liver.

Mucous cells secrete?

Mucous and small amounts of pepsinogen

Is skeletal muscle nucleated?

Multinucleted

How does myosin generate force in skeletal muscle?

Multiple myosin II molecules generate force in skeletal muscle through a power stroke mechanism fuelled by the energy released from ATP hydrolysis. The power stroke occurs at the release of phosphate from the myosin molecule after the ATP hydrolysis while myosin is tightly bound to actin. The effect of this release is a conformational change in the molecule that pulls against the actin. The release of the ADP molecule and binding of a new ATP molecule will release myosin from actin. ATP hydrolysis within the myosin will cause it to bind to actin again to repeat the cycle. The combined effect of the myriad power strokes causes the muscle to contract.

_____ neurons are most of the neurons in the brain.

Multipolar

The percentage by volume of red blood cells is called the _____.

Hematocrit, which is normally 35-55% and is greater in men than in women.

What does heme do in the peroxisome?

Heme binds with catalase in the peroxisome to degrade hydrogen peroxide.

Archaea supercoils have ______, whereas bacteria supercoils have ______.

Histones; proteins different from histones.

The parents of a dihybrid cross are genetically ______ at the genes of interest.

Identical, for example, AaBb x AaBb

If blood calcium levels fall, ________ is produced by the _______ in order to increases calcium levels to homeostasis.

If blood calcium levels fall, PTH is produced by the parathyroid gland in order to increase blood calcium levels to homeostasis.

If blood calcium levels rise, ________ is produced by the _______ in order to decrease blood calcium levels to homeostasis.

If blood calcium levels rise, calcitonin is produced by the thyroid gland in order to decrease blood calcium levels to homeostasis, this occurs by calcium salt deposition in bone.

What would be a consequence if damaged cells failed to undergo apoptosis?

If damaged cells fail to undergo apoptosis, the result may be cancer.

What happens to the negative feedback loop of T3 and T4 if there is no Iodine present in the body?

If no iodine is present in the body, there is no inhibition of the T3 and T4 pathway and the individual with develop Goiter... - Goiter is the undifferentiated growth of the thyroid gland. - this is because, if there is no iodine, no T3 or T4 can be produced, thus there will be no negative feedback to shut down hypothalamus and ant. pit., thus thyroid will continue to grow.

If there is no oxygen present after glycolysis, where do the 2 pyruvate molecules go?

If no oxygen is present, the pyruvate molecules are fermented into lactic acid.

If there is oxygen present after glycolysis, where do the 2 pyruvate molecules go?

If oxygen is present, pyruvate and NADH enter The Krebs cycle and ETC in the mitochondrial matrix. Since the outer membrane of the mitochondria is permeable to small molecules, both pyruvate and NADH pass via facilitated diffusion.

Will the bacteria be gram positive or negative if it has a thick PD cell wall?

If the bacteria has thick PD cell walls, it will be gram positive because the stain will be stuck in the PD. - It will look purple

What hormone is released by the small intestine if chyme is particularly fatty and what does it do?

If the chyme is particularly fatty, the duodenum releases the hormone enterogastrone, which inhibits stomach peristalsis, slowing the release of chyme into the small intestine, allowing the enzymes (lipase) to breakdown the fats more.

What effect does PTH have on blood calcium levels, and how does it do this?

PTH increases blood calcium levels in 2 different ways: 1- PTH increases blood calcium by stimulating osteoclasts to break bone down and release calcium. This occurs because PTH increases osteocyte absorption of calcium and phosphate from bone, thus stimulating the proliferation of osteoclasts. 2- PTH increase renal calcium reabsorption 3- PTH increases calcium and phosphate uptake from the gastrointestinal tract, thus increasing renal production of the steroid 1,25-dihydroxycholecalciferol derived from vitamin D.

PTH _______ plasma calcium levels; while Calcitonin _______ plasma calcium levels.

PTH increases plasma calcium levels; while Calcitonin decreases plasma calcium levels.

What effect does PTH have on plasma phosphate levels?

PTH is the major regulator of serum phosphate concentrations via actions on the kidney. It is an inhibitor of proximal and also distal tubular reabsorption of phosphorus. Therefore, PTH increases renal excretion of phosphate, thus lowering blood levels. Through activation of Vitamin D the absorbtion of Phosphate is increased.

What regulates the secretion of PTH?

PTH secretion is regulated by the calcium ion plasma concentration, and the parathyroid glands shrink or grow accordingly.

The _____ acts as both an endocrine and exocrine gland.

Pancreas

Which organ is located under and behind the stomcah?

Pancreas

_______ ______ hydrolyzes polysaccharides to disaccharides and trisaccharides; however, ____ ____ is much more powerful than its salivary counterpart.

Pancreatic amylase - degrades nearly all the carbohydrates from the chyme into small glucose polymers, via carbohydrate hydrolysis. - the brush border enzymes finish degrading these polymers to their respective monosaccharides before they are absorbed. - hydrolyzes starch to maltose and is activated by trypsin

Why are pancreatic enzymes secreted in zymogen or inactive form?

Pancreatic cells are not as easily replaced as intestinal epithelium and thus cannot risk the damage caused by the active enzymes.

What type of cells produce and secrete glucagon?

Pancreatic α-cells

What type of cells produce and secrete insulin?

Pancreatic β-cells

When a symbiosis is beneficial for one species and detrimental for the other, it is called ____?

Parasitism

Parasympathetic NS has ____ preganglionic neurons that synapse basically on the effector organ; while the Sympathetic NS has ____ preganglionic neurons that synapse in the sympathetic chain ganglion, and _____ postganglionic neurons.

Parasympathetic NS has long preganglionic neurons that synapse basically on the effector organ; while the Sympathetic NS has short preganglionic neurons that synapse in the sympathetic chain ganglion, and long postganglionic neurons.

Most of the internal organs are innervated by both the ______ and the _____ systems, working ________ to each other.

Parasympathetic and sympathetic systems; antagonistically to each other.

What are the two divisions of motor portion of the ANS?

Parasympathetic: Rest and digest Sympathetic: Fight or flight

Which hormone stimulates osteoclast activity?

Parathyroid Hormone

_____ is a peptide hormone that increases blood calcium levels.

Parathyroid hormone; PTH

______ cells also secrete intrinsic factor, which helps the ileum absorb B12.

Parietal cells

_________ acetylcholine receptors are acetylcholine receptors that form G protein-receptor complexes in the cell membranes of certain neurons and other cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system.

Muscarinic: - Muscarinic receptors were named as such because they are more sensitive to muscarine than to nicotine. Their counterparts are nicotinic acetylcholine receptors (nAChRs), receptor ion channels that are also important in the autonomic nervous system. Many drugs and other substances (for example pilocarpine and scopolamine) manipulate these two distinct receptors by acting as selective agonists or antagonists

Muscle fibres/cells are bound together to form a muscle fasciculus and many muscle fasciculi are wrapped together to form a ____.

Muscle

______ cells are also found within the exocrine glands/gastric pits of the stomach. They secrete HCl (Hydrochloric acid), which diffuses to the lumen of the stomach to help breakdown of macromolecules.

Parietal cells of oxyntic cells.

What are the partial pressures of Oxygen and carbon dioxide in the lungs, and what roles do these partial pressures play?

Partial pressure of Oxygen is 110mmHg and Carbon Dioxide is 40mmHg. Thus, under these pressures, oxygen diffuses into the capillaries of the lungs and carbon dioxide diffuses from the capillaries to the alveoli of the lungs. Thus, CO₂ is exhaled out.

What is it called when molecules move through leakage channels across the membrane due to random motion?

Passive Diffusion

How is the membrane brought back to its resting potential?

Passive diffusion returns the membrane to its resting potential. - The entire process just described is called the action potential. - The Na⁺/K⁺ pump keeps working through out the action potential.

What sort of plants did Mendel use to perform his experiments?

Pea plants

_______ refers to the proportion of individuals with a specific genotype who have the corresponding phenotype.

Penetrance: - In Incomplete penetrance, a dominant allele is not always expressed in the heterozygous individuals or a recessive allele is not always expressed in the homozygous recessive individual

What do penicillin and the enzyme lysozyme do to bacterial cell walls?

Penicillin attacks the amino acids crosslinks of PD and lysozyme attacks the disaccharide linkage in PD, both causing the cell to lyse

What enzymes digest proteins?

Pepsin in the stomach and; Trypsin and chymotrypsin and brush border enzymes in the duodenum.

How is pepsinogen activated to pepsin and what does pepsin digest?

Pepsinogen is cleaved by the low pH of the stomach to the active pepsin. -Pepsin digests proteins.

Chief (peptic) cells secrete:

Pepsinogen, the zymogen precursor to pepsin.

What are the must know Peptide Hormones?

Peptide Hormones of the: 1. Anterior Pituitary gland: FSH, LH, ACTH, HGH, TSH, Prolactin 2. Posterior Pituitary gland: ADH and oxytocin 3. Parathyroid hormone or PTH 4. Pancreas: glucagon and insulin

Describe the peptide hormones:

Peptide Hormones: - derived from peptides, may be large or small, often include carbohydrate portions - since they are peptide derivatives, peptide hormones are water soluble, and thus move freely through the blood, but have difficulty diffusing through the cell membrane of the effector (target cell of the hormone), thus instead of diffusing through the cell, the peptide hormones attach to a membrane-bound receptor.

____ _____ is a covalent chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, causing the release of a molecule of water (H2O), hence the process is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids.

Peptide bonds between amino acids forms proteins

Since ____ ______ are proteins, they cant diffuse through the cell membrane, so they bind to receptors on the membrane and act through a second messenger.

Peptide hormones

_____ hormones are fast acting, but short living; while _____ hormones are slow acting and long living.

Peptide hormones are fast acting, but short living; while steroid hormones are slow acting and long living.

What is the cell wall of a bacterium made of?

Peptidoglycan: a series of disaccharide polymer chains with amino acids. - these chains are connected by their amino acids, or cross-linked by an interbridge of more amino acids. - The chains are continuous, forming a single molecular sac around the bacterium - PD is more elastic than cellulose - PD is also porous, allowing large molecules to pass through. - Archaea do not have PD walls.

Muscle contraction occurs when ____ globular heads crawl along an ____ filament in a five-stage cycle.

Muscle contraction occurs when myosin globular heads crawl along an actin filament in a five-stage cycle.

What is the difference in motor units between muscles requiring intricate movements vs muscles that require lots of force?

Muscles requiring intricate movements, like those in the fingers, have smaller motor units, whereas muscles requiring greater force, such as those in the back, have larger motor units.

What is meant by Mutational Equilibrium?

Mutational Equilibrium means that the rate of forward mutations exactly equals the rate of back mutations. - this rarely occurs in real populations - however, in the short term, mutations are seldom a major factor in changing allelic frequencies.

When a symbiosis benefits both species, it is called _____?

Mutualism

Define Diastole:

Period of time after systole, when the heart fills with blood. - lowest blood pressure due to no blood being pumped out of heart. - Ventricular diastole is the period during which the ventricles are relaxing, while atrial diastole is the period during which the atria are relaxing. - occurs during relaxation of the whole heart and then contraction of the atria to fill the ventricles.

The ___ nervous system handles the sensory and motor functions of the nervous system.

Peripheral

What are nails?

Nails are keratinized cells as well.

What are the proteins called that are situated entirely on the outside surfaces of the membrane?

Peripheral or extrinsic; they are ionically bonded to integral proteins or the polar head group of a lipid.

Peripheral tissue has a ____ shifted curve while the lungs have a ____ shifted curve.

Peripheral tissue has a right shifted curve while the lungs have a left shifted curve.

What are natural killer cells and what do they do?

Natural Killer cells are a special type of cytotoxic lymphocyte, they play a major role in the refection of tumours and cells infected by viruses. - NK cells can attack virtually any infected cell, even if it has not yet been marked for destruction by the immune system

What is reabsorbed into the blood from the Distal convoluted tubule?

Na⁺, Ca²⁺

Which are the two cells types that store large amounts of glycogen?

Nearly all cells are capable of producing and storing some glycogen; however, only muscle cells and especially liver cells store large amounts.

What is the space between the PD cell wall and the PM called?

Periplasmic Space, which contains many proteins used to acquire nutrition

Why does skeletal muscle NOT contribute to peristalsis?

Peristalsis is a function of smooth muscle only and has nothing to do with skeletal muscle.

What is the likelihood that two genes, located on the same chromosome will remain together during gamete formation?

If two genes are located on the same chromosome, the likelihood that they will remain together during gamete formation is indirectly proportional to the distance separating them. - thus, the closer the genes are together on the same chromosome, the more likely they will remain together.

What is it called if one of the products downstream in a reaction series comes back and inhibits the enzymatic activity in an early reaction?

Negative feedback or feedback inhibition

Which filaments contract during muscular contraction?

Neither the thin nor the thick filaments contract, instead, the proportion of myosin and actin that overlap increases.

The ___ ___ allow for rapid and direct communication between specific parts of the body resulting in changes in muscular contractions or glandular secretions.

Nervous System; - included in the nervous system is the brain, spinal cord, nerves and neural support cells and certain sense organs such as the eye and the ear.

Neuron processes are typically bundled together to form ____ (called ___ in the CNS).

Neuron processes (axons and dendrites) are typically bundled together to form nerves (called tracts in the CNS).

What is the functional unit of the nervous system?

Neuron; the neuron is so highly specialized that it has lost the ability to divide, thus it is permanently in G0 phase of its life cycle. - the neuron depends almost entirely on glucose for its chemical energy. - the neuron uses facilitated transport to take glucose into the cytosol, unlike other cells however, the neuron is not dependent upon insulin for this transport. - the neuron depends heavily on the efficiency of aerobic respiration - the neuron has low stores of glycogen and oxygen thus relies on blood to supply sufficient levels of these nutrients.

____ _____ tends to be rapid, direct, and specific. _____ ______, on the other hand, tends to be slower, spread throughout the body, and affect many cells and tissues in many different ways.

Neuronal communication; Hormonal communication

Formation of the neural tube?

Neurulation

In _________, the notochord (made from the mesoderm) induces the overlying ectoderm to thicken and form the neural plate.

Neurulation: is the stage of organogenesis in vertebrate embryos, during which the neural tube is transformed into the primitive structures that will later develop into the central nervous system

What is the leukocyte composition of the blood?

Neutrophils 62% Lymphocytes 30% Monocytes 5.3% Eosinophils 2.3% Basophils 0.4%

What appears on the scene after macrophages in order to attack the infectious agents?

Neutrophils appear after the macrophages - most neutrophils are stored in the bone marrow until they are needed, but some are found circulating in the blood or in the tissues. - neutrophils move toward the infected or injured area, drawn in by chemicals released from damaged tissues or by the infectious agents themselves... called chemotaxis

Where are Archaea normally found?

In extreme environments such as salty lakes and boiling hot springs.

What does increased estrogen during the latter half of the proliferative/follicular phase cause?

Increased estrogen from the growing follicles stimulates GnRH secretion from the hypothalamus.... this causes the surge of LH and FSH through positive feedback. This causes the luteal surge and ovulation or the bursting of the follicle

What does blockage of the canal of Schlemm cause?

Increases intraocular pressure resulting in one form of glaucoma and possibly blindness.

When does induction occur?

Induction occurs when one cell type affects the direction of differentiation of another cell type.

What is cell-mediated immunity effective against?

Infected cells

Part of the effect of _____ is to 'wall-off' the effected tissue and local lymph vessels from the rest of the body, impeding the spread of the infection.

Inflammation

What is Inflammation?

Inflammation is a vascular tissue response to harmful stimuli, such as pathogens, damaged cells or irritants. - This response is a protective attempt to stop the stimulus from spreading to other tissues and to initiate the healing process.

What results from injury to tissues?

Inflammation, which includes dilation of blood vessels, increased permeability of capillaries, swelling of tissue cells, and migration of granulocytes and macrophages to the inflamed area.

During _____, the diaphragm contracts by moving down and flattening from its original dome-shaped position.

Inhalation - rib cage expands as rib muscles contract (external intercostals contract), volume of chest cavity (thoracic) expands - causing negative pressure in the chest/lungs, thus the atm pressure forces air into lungs

Do T lymphocytes make free antibodies?

Never

What happens to the primary follicle?

Next, Theca cells differentiate from the interstitial tissue and grow around the follicle to form a secondary follicle.

The way in which a species exploits its environment is called its ____.

Niche: no two species can occupy the same niche indefinitely.

_______ is the alternating contraction and relaxation of the smooth muscles that propels the bolus through the digestive tract.

Peristaltic Action: - peristaltic action is a wave motion, similar to squeezing a tube of toothpaste at the bottom and sliding your fingers toward the top to expel the toothpaste.

______ acetylcholine receptors are cholinergic receptors that form ligand-gated ion channels in the plasma membranes of certain neurons and on the postsynaptic side of the neuromuscular junction. As ionotropic receptors, _____ _____ ______ are directly linked to ion channels and do not use second messengers (as metabotropic receptors do).

Nicotinic Acetylcholine Receptors - Like the other type of acetylcholine receptor—the muscarinic acetylcholine receptor (mAChR)—the nAChR is triggered by the binding of the neurotransmitter acetylcholine (ACh). However, since muscarinic receptors are also activated by muscarine, nicotinic receptors can be opened by nicotine—hence the name "nicotinic."

What effect does Nitrogen have on the body?

Nitrogen is very stable due to its triple bond. - it diffuses into the blood but does NOT react with the chemicals in the blood.

Do viruses lose their ability to infect once crystallized?

No

Prokaryotes have no ____?

No Nucleus

Does any digestion occur in the esophagus?

No digestion occurs in the esophagus.

Are immigration and emigration of alleles in the gene pool a major factor in changing allelic frequencies?

No, it may occur in some isolated populations, but is not typically a major factor in genetic change.

Are viruses classified as living organisms?

No, not currently. They do not belong to any taxonomical kingdom of organisms.

Do viruses have a barrier that separates them from the external environment?

No, unlike living organisms, viruses in their active form are not separated from their external environment by some type of barrier such as a cell wall or membrane.

Can a person with Type A blood donate to a person with Type B blood or vice versa?

No. A person with Type A blood with produce B antibodies and a person with B blood will produce A antibodies

____ ___ _____ are the tiny gaps between the myelin on the axon. The action potential jumps from node to node.

Nodes of Ranvier

Bind non-covalently to an enzyme at a spot other than the active site and change the conformation of the enzyme.

Noncompetitive Inhibitors: - do not prevent substrate from binding, and they bind just as easily to enzymes bound to substrate as to enzymes not bound to substrate. - they do not resemble the substrate, so they can act on more than one type of enzyme.

The perpendicular force to an object is also called the ______ force.

Normal Force, Fn.

Nucleotides form polymers to create ____ ____, ____ and ____.

Nucleic acids, DNA and RNA

What is the complex called in bacteria that contains the DNA, RNA and proteins?

Nucleoid; also called the chromatin body, nuclear region, nuclear body. The nucleoid is not enclosed by a membrane since bacteria have not membrane bound organelles.

What two organelles in Eukaryotic cells have DNA?

Nucleus and Mitochondria

What organelles exist in the Eukaryotic Cell?

Nucleus, RER, SER, Nucleolus, Golgi, Mitochondrion, Peroxisome, Lysosome, centrosome, centrioles, ribosomes, flagellum, Microvilli

______ are vesicles in the cytosol, they grow by incorporating lipids and proteins from the cytosol.

Peroxisomes: - self-replicate - they are involved in the production and breakdown of hydrogen peroxide. - Inactivate toxic substances such as alcohol, regulate oxygen concentration, play a role in the synthesis and the breakdown of lipids, and in the metabolism of nitrogenous bases and carbohydrates.

How does Phagocytosis work?

Phagocytosis is accomplished by the binding of proteins on the particulate matter to protein receptors on the phagocytotic cell. In humans, antibodies or complement proteins bind to particles and stimulate receptor proteins on macrophages and neutrophils to initiate phagocytosis. Once the particulate matter is engulfed, the membrane bound body in the cytoplasm is called a phagosome.

________ wrap many times around axons in the CNS creating electrically insulating sheaths called Myelin.

Oligodendrocytes: - cells that coat axons in the central nervous system (CNS) with their cell membrane forming a specialized membrane differentiation called myelin, producing the so-called myelin sheath. The myelin sheath provides insulation to the axon that allows electrical signals to propagate more efficiently.

What does the secretion of gastrin from G cells cause?

Once Gastrin is secreted into the interstitium, it is absorbed into the blood and it stimulates the release of HCl from parietal cells.

What is the absolute refractory period?

Once an AP has begun, there is a short period of time called the absolute refractory period in which NO stimulus will create another action potential.

What happens to all 3 sugars/carbohydrates once in the liver?

Once in the liver galactose and fructose are converted to glucose

What does the steroid hormone do once inside the cell cytosol?

Once inside the cytosol of the effector cell, the steroid hormone binds to a steroid receptor in the cytosol. The receptor then transports the steroid hormone into the nucleus, where the steroid hormone acts on the DNA at the transcription level. - Steroid hormones are transcription factors.

What happens to each polypeptide once it has entered the enterocyte?

Once inside the enterocyte, intracellular enzymes break the polypeptides down into their amino acid constituents.

What happens when Theca cells are stimulated by LH?

Once stimulated by LH, theca cells secrete androgen, which is converted to estradiol by the granulosa cells in the presence of FSH and secreted into the blood. - The follicle then grows and bulges from the ovary.

After the blastocyst implants into the uterine wall on the 5th to 7th day after ovulation and subsequent fertilization, what does the embryo then become?

Once the blastocyst is implanted into the uterine wall, the gastrula is formed in the second week after fertilization in a process called gastrulation. - this is when the cells begin to slowly move about the embryo for the first time.

Where do the chylomicrons go from the enterocytes?

Once the chylomicrons leave the enterocyte, they move into the lacteal (lymphatic system) and empty into the large veins of the neck through the thoracic duct. - these chylomicrons/fat are then moved to the liver or adipose tissue.

What do the theca cells do?

Once the secondary follicle is created from theca cells surrounding the primary follicle, Theca cells are stimulated by LH to secrete androgens which are converted to estradiol. Androgens are converted to estradiol by the granulosa cells in the presence of FSH and then secreted into the blood.

What happens to the spermatozoon once it is freed from the sertoli cells of the testes into the tubule lumen?

Once the spermatozoon is freed from the sertoli cells, it is carried to the epididymus where it is stored, acquires motility and mature until ejaculation.

What is one important function of plasma proteins?

One important function of plasma proteins is to act as a source of amino acids for tissue protein replacement.

How do we classify viruses?

One way to classify them is by the type of Nucleic acid they possess: 1) Unenveloped plus-strand RNA is responsible for the common cold.. Not all viruses need to be enveloped and the 'plus-strand' means that proteins can be directly translated from RNA. 2) Enveloped plus-strand RNA viruses include retroviruses- HIV. 3) Minus-strand RNA viruses: include measles, rabies, and the flu. - minus strand RNA is a complement to mRNA and must be transcribed to plus-strand RNA before being translated 4) Double stranded RNA viruses 5) Single stranded DNA viruses 6) Double stranded DNA viruses

When will the secondary oocyte complete meiosis II?

Only after fertilization does the secondary oocyte in the fallopian tube complete meiosis II (equational division), subsequently forming a second polar body and a haploid ovum.

Where is glucose absorbed into the body?

Only certain epithelial cells of the digestive tract and the proximal tubule of the kidney are capable of absorbing glucose against a concentration gradient. This is done via a secondary active transport mechanism down the concentration gradient of sodium. All other cells absorb glucose via facilitated diffusion.

Which part of the Spermatozoon enters the egg?

Only the nuclear portion of the head.

When and where does oogenesis begin?

Oogenesis begins in the ovaries of the fetus.

What is the female process of gametogenesis called?

Oogenesis: which is the creation of an ovum or egg cell.

Describe the pressures that exist through out the capillary bed, between the arterioles and the venules:

Osmotic pressure is constant through out the capillary bed. It remains the same from the arteriole end all the way to the venule end of the capillary. - Hydrostatic pressure is greatest at the arteriole end of the capillary and decreases towards the venule end. - Thus, there is greater fluid flow out of the capillary near the arteriole end compared to the smaller fluid flow into the capillary near the venule end. The net fluid flow into the capillary near the venule end is due to the osmotic pressure (constant) being greater than the decreased hydrostatic pressure at this point. This creates the 10% fluid loss into the interstitium, which then travels into the lymphatic system. - thus, net flow out of capillaries is greater than net flow in by 10%

Define osmotic pressure:

Osmotic pressure is the pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane.[1] It is also defined as the minimum pressure needed to nullify osmosis.

Bone forming ______ differentiate from fibroblasts of the perichondrium.

Osteoblasts

What do osteoblasts differentiate into after they are enveloped by the matrix?

Osteoblasts differentiate into osteocytes

____ secrete collagen and organic compounds upon which bone is formed.

Osteoblasts: - they are incapable of mitosis - as osteoblasts release matrix materials around themselves, they become enveloped by the matrix and then differentiates into osteocytes.

______ resorb bone matrix, releasing minerals, such as calcium, back into the blood.

Osteoclasts: - osteoclasts are believed to develop from the white blood cells called monocytes.

Which cell arises from the same stem cell in the bone marrow as an erythrocyte?

Osteoclasts: they differentiate from phagocytic blood cells and all blood cells differentiate from the same precursor!

How do osteocytes connect to other osteocytes?

Osteocytes make contact with the cytoplasmic processes of their counterparts via a network of small transverse canals, or canaliculi.

Describe how the voltage gated sodium channels contribute to depolarization:

These proteins change configuration when the voltage across the membrane is disturbed. - They allow Na⁺ to flow through the membrane for a fraction of a second as they change configuration. - As Na⁺ flows into the cell, the voltage changes further, causing more sodium channels to change configuration, allowing still more sodium to flow into the cell in a positive feedback mechanism. - Since the Na⁺ concentration moves toward equilibrium, and the K⁺concentration remains higher inside the cell, the membrane potential actually reverses polarity so that it is positive on the inside and negative on the outside. This is called depolarization.

What is one thing that is true of all endocrine hormones?

They all bind to a protein receptor: Steroid Hormones bind to protein in cytosol Peptide Hormones bind to cell surface protein receptor Tyrosine Derivative Hormones bind to a protein receptor in the Nucleus

From what and where do the agranular and granular forms derive?

They all derive from pluripotent stem cells (myeloid and lymphoid) in the bone marrow.

How do viruses reproduce?

They always reproduce within the host cell, they always require the host cell's reproductive machinery to do so. - Viruses do not metabolize organic nutrients

Describe Eicosanoids:

They are a 20-carbon fatty acid that include prostaglandins, thromboxanes, and leukotrienes. They are released from cell membranes as local hormones (autocrine/paracrine) that regulate, among other things, blood pressure, body temp, and smooth muscle contraction.

Where are uric acid, bile pigments, antibiotics and other drugs secreted into the filtrate?

They are all secreted into the filtrate or primary urine through the cells of the proximal tubule.

What single feature of phospholipids makes them especially well suited as the major component of biological membranes?

They are amphipathic

What happens to all carbohydrates once digested?

They are delivered to the body cells after being converted to glucose by the liver or enterocytes

Where are glycolipids found?

They are found in abundance in the membranes of myelinated cells composing the human nervous system.

Why is a paper bag given to someone who is experiencing hyperventilation?

They are losing too much CO₂ by breathing, so blood pH is rising, creating concern for alkalosis. - the paper bag allows them to inhale CO₂ and thus lower pH of blood

What do cytotoxic T-cells do?

They are part of the immune response, they bind to and destroy infected cells.

Describe the function of the mucous cells of the stomach epithelium:

They are perform the same function: to secrete mucous. - the mucous cells line the stomach wall and the necks of the exocrine glands/gastric pits. - Mucous, made mainly of sticky glycoproteins and electrolytes, lubricates the stomach wall so food can slide along its surface without causing damage, and mucous also protects the epithelial lining from the acidic environment of the stomach. - Some mucous cells also secrete a small amount of pepsinogen.

What happens to the endocytotic vesicles made at the cell membrane?

They are shuttled back to the golgi for recycling of the cell membrane.

What are the catecholamines also considered to be based on their "fight-or-flight" response?

They are thus considered stress hormones as well.

What happens to monocytes once they are deposited into tissues?

They become macrophages where they can live for years.

What do trypsin and chymotrypsin do?

They both degrade proteins into small polypeptides via protein hydrolysis. - trypsin is also an activator of all other pancreatic zymogens.

How do large lipid soluble molecules like steroid hormones move through membranes?

They can pass right through the membrane

What happens to the neutrophils and macrophages once they engulf necrotic tissue and bacteria?

They die. These dead leukocytes, along with the fluid and necrotic tissue, make up the pus from an infection.

How do feedback inhibitors work?

They do not resemble the substrate of the enzyme that they inhibit. They bind to the enzyme and cause a conformational change, called Allosteric Regulation.

What do the fenestrations of the glomerular endothelium do?

They filter out large proteins and blood cells from entering Bowman's capsule.

Where do the newly synthesized proteins of the RER go next?

They go to the golgi complex via the lumen of the ER. The golgi complex is a series of flattened, membrane bound sacs. Small transport vesicles bud off from the ER and carry the proteins across the cytosol to the golgi.

Describe Type II B or fast twitch II B muscle fibres:

They have a low myoglobin content, thus they appear white and contract very rapidly. - they contain large amounts of glycogen.

How are lipoproteins attached to membrane?

They have their lipid portions embedded in the membrane and their protein portion at the surfaces.

What does it mean that most fungi are saprophytic?

They live off of dead and rotting organic matter. - not all fungi are saprophytic and thus cause a pathogenic concern for humans

What can be said since organisms within the same taxonomical group have similar genetic structures?

They must share similar phylogenies or evolutionary histories.

Why are enzymes required by all living things?

They properly orient reactants and lower activation energy

How do the neutrophils enter the damaged or infected tissue?

They slip between endothelial cells of the capillary walls, using an amaeboid-like process called Diapedesis.

Why is it that the lymph nodes of the neck swell from a cold or other sickness?

They swell as white blood cells proliferate within them to fight the infection

Where do viruses get ATP?

They use the ATP made available by the host cell.

What happens to the small amounts of more water soluble fatty acids in the duodenum?

They would be absorbed directly into the blood of the villi.

How are the thin and thick filaments of smooth muscle organized?

Thin and thick filaments in smooth muscle cells are attached to the intermediate filaments, and, when they contract, they cause the intermediate filaments to pull the dense bodies together.

What is the main purpose of the entire process of the kidneys?

This entire process allows for high concentrated urine to be excreted while water and other important nutrients are reabsorbed back into the blood by the kidneys.

What is the Hardy-Weinberg Principle?

This equilibrium explains how the less frequent alleles are maintained in a population. - states that both allele and genotype frequencies in a population remain constant—that is, they are in equilibrium—from generation to generation unless specific disturbing influences are introduced. Those disturbing influences include non-random mating, mutations, selection, random genetic drift, gene flow and meiotic drive. It is important to understand that in real populations, one or more of these "disturbing influences" are always in effect. That is, Hardy-Weinberg equilibrium is an ideal state that provides a baseline against which change can be analyzed.

What is depleted first in the body of an athlete performing maximal exercise?

Phosphocreatine

Phospholipids:

Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline. The structure of the phospholipid molecule generally consists of hydrophobic tails and a hydrophilic head. It is usually found with cholesterol molecules which are found in-between the spaces of the phospholipid.

Based on the Oxygen Dissociation curve, what does the flat area at the top represent?

This flat area shows that small fluctuations in oxygen pressure have little effect on percent saturation of Hb with oxygen.

What does the area of the curve that sharply climbs indicate?

This indicates that with small changes in oxygen pressure follow large changes in Oxygen saturation of Hb.

What effect do high plasma levels of T3 and T4 have on TRH and TSH secretion?

This is a negative feedback mechanism wherein high levels of T3 and T4 inhibit TRH release from the hypothalamus and also inhibit TSH release from the ant. pit.

What is the area called and where is it located where a bone continues to grow in length?

This is a sheet of cartilage located in the metaphysis, called the epiphyseal plate.

What is the SRY area of the Y-chromosome?

This is the sex-determining Region Y, which has been implicated in initiating male sex determination

When a blood type is termed negative, as in type B negative, what does it mean?

This means that the person with Type B blood carries the B antigen on the RBC but NOT the Rh factor. - it does not carry A antigen - It does produce A antibodies and Rh antibodies

When it is said that a women is a carrier of a trait, what is meant?

This means that the woman carries a sex-linked recessive trait on one of her 23rd chromosomes, and that it has a high chance of being expressed in her offspring.

Since the interstitial fluid is an aqueous solution, and fat thus clumps together, reducing its surface area, how is lipase able to degrade the fat?

This problem is solved via the addition of bile which is produced in the liver and stored in the gall bladder. The bile acts to increase the surface area of the fat by physically separating the molecules of fat in order to allow lipase to break the fat down. - Bile does not break any fat down, only separates molecules from each other.

Why was it such an issue when doctors would prescribe numerous antibiotics at once to their patients?

This promoted conjugation of different R plasmids providing different resistances to antibiotics to produce a super-bacterium that contains many antibiotics resistances on one or more R plasmids

What does the surge of progesterone from the corpus luteum during the secretory/luteal phase cause?

This surge of progestrone causes the glands of the endometrium to mature and prepare for implantation of an embryo.

Increasing the duration of ventricular diastole would serve what purpose?

This would increase the period of time the heart fills with blood, thus would decrease cardiac output and decrease blood pressure

What would permanent sequestering of calcium in the sarcoplasmic reticulum lead to?

This would prevent calcium from leaving the sarcoplasmic reticulum and binding to troponin, which is what causes the conformational change that moves tropomyosin away from the myosin binding sites/active sites on actin filaments. Thus, if no calcium is able to leave the SR and bind troponin, no myosin would be able to bind to the actin active sites and thus there would be no muscle contractions.

Where is the velocity of blood the slowest in the body?

Through the capillaries

What is the specific target tissue for TSH?

Thyroid gland

What stimulates the thyroid to release T3 and T4?

Thyroid-Stimulating hormone, TSH, via the anterior pituitary gland stimulates the thyroid to secrete T3 and T4

______-_____ hormone, also called Thyrotropin, is a tropic peptide hormone, released from the anterior pituitary that stimulates the thyroid to release T3 and T4 via the second messenger system using cAMP.

Thyroid-stimulating hormone (TSH):

Which hypothalamus hormone stimulates the anterior pituitary to release PRL?

Thyrotropin Releasing Hormone; TRH

Which hypothalamus hormone stimulates the anterior pituitary to release TSH?

Thyrotropin-releasing hormone, TRH

_____ _____ form a water tight seal from cell to cell that can block water, ions, and other molecules from moving around and past cells.

Tight Junctions: - tissues held together by tight junctions may act as a complete fluid barrier. - Epithelial cells in organs like the bladder, intestines, and kidneys are held together by tight junctions in order to prevent waste materials from seeping around the cells into the body. - tight junctions also act as a barrier to protein movement between the apical and the basolateral surface of a cell. - essentially, tight junctions are fluid barriers around cells.

Why are septa (fungal cell walls) perforated?

To allow the exchange of cytoplasm between cells, called cytoplasmic streaming.

How is the platelet membrane designed?

To avoid adherence to healthy endothelium while adhering to injured endothelium.

How do you carry out a monohybrid cross?

To carry out such a cross, each parent is chosen to be homozygous or true breeding for a given trait (locus). When a cross satisfies the conditions for a monohybrid cross, it is usually detected by a characteristic distribution of second generation (F2) offspring that is sometimes called the monohybrid ratio.

What is the purpose of the fluid exchange that occurs in the capillaries?

To control for inflammation, blood flow, blood pressure, tissue fluid (edema), gas exchange and body temp.

What is the main role of the respiratory system?

To deliver oxygen to the blood and expel carbon dioxide

What are the 2 main roles of the low pH of the stomach?

To denature proteins and kill bacteria.

What is the function of the auricle or pinna?

To direct the sound wave into the external auditory canal.

What is a typical effect of Steroid hormones on the cell?

To increase certain membrane or cellular proteins within the effector cell.

What is the function of gap junctions in the intercalated disc of cardiac muscle?

To insure that an AP is spread to all fibres in the muscle network.

What is the function of the CNS?

To integrate nervous signals between sensory and motor neurons.

Why does a cardiac muscle cell remain depolarized much longer than a neuron during an AP?

To precent the initiation of another action potential during contraction of the heart.

What is the role of the lysozyme within the small intestine?

To regulate the bacteria

Where does the filtrate go from the ascending loop of Henle?

To the distal convoluted tubule.

What is the role of Red Blood Cells?

To transport/deliver oxygen and remove CO₂

Why is the concentration of free Ca²⁺ ions in the blood the physiologically important form of calcium?

Too much Ca²⁺ results in cellular membrane becoming hypo-excitable producing lethargy, and memory loss; too little produces cramps and convulsions.

What are the first 8 cells formed during cleavage said to be?

Totipotent, meaning they have the potential to express any of their genes. They are all the same size and shape. - any of these eight cells at this stage could produce a complete individual.

Most steroids regulate enzymatic activity at the level of?

Transcription

What occurs on the RER?

Translation on the RER propels proteins into the ER lumen as they are created. These proteins are tagged with signal sequences of amino acids and sometimes glycosylated via the addition of carbohydrates.

When a proximal tubule transport protein becomes saturated, what is the concentration of the solute that saturates its transport proteins called?

Transport Maximum

What sort of transport brings the amino acids into the cells of the body?

Transport into the cell may be facilitated or active, but never passive, since amino acids are too large and polar to diffuse through the membrane.

What does most of our dietary fat consist of?

Triglycerides

What are triglycerides broken down into?

Triglycerides -> monoglycerides and fatty acids

A _____ peptide hormones released from the hypothalamus, is released into the blood stream and affects another endocrine gland and controls other hormone releases.

Tropic

What are the 2 proteins that are attached to actin thin filament?

Troponin and tropomyosin

How are all the pancreatic enzymes activated?

Trypsin is activated by the enzyme enterokinase located in the brush border of the small intestine. The activated form of trypsin then activates all other pancreatic enzymes.

Describe Type II A or fast twitch II A muscle fibres:

Type II A muscle fibres are also red, but they split ATP at a high rate. - Type II A fibres contract rapidly - Type II A fibres are resistant to fatigue but not as resistant as type I fibres

What type of antigens and antibodies does a person with Type O blood have?

Type O blood has neither A or B antigens. This person's immune system makes both A and B antibodies

Describe the relative pressures between lymph fluid and interstitial fluid:

Typically, interstitial fluid pressure is slightly negative. as the interstitial pressure rises toward zero, lymph flow increases.

Which type of motor units are the first to be activated?

Typically, smaller motor units are the first to be activated, and larger motor units are recruited as needed. - this results in a smooth increase in the force generated by the muscle.

What do the microvilli look like under a light microscope and what is this called?

Under a light microscope the microvilli look like a fuzzy covering called the Brush Border.

_______ neurons are sensory only.

Unipolar

How many nuclei does each cardiac muscle cell contain?

Unlike skeletal muscle, each cardiac muscle cell only contains one nucleus and the cardiac muscle cell is separated from its neighbour via and intercalated disc.

Unsaturated Fatty Acids:

Unsaturated fatty acids have one or more double bonds between carbon atoms. (Pairs of carbon atoms connected by double bonds can be saturated by adding hydrogen atoms to them, converting the double bonds to single bonds. Therefore, the double bonds are called unsaturated.) The two carbon atoms in the chain that are bound next to either side of the double bond can occur in a cis or trans configuration.

__________ fats have a lower melting point and are more likely to be liquid. ________ fats have a higher melting point and are more likely to be solid.

Unsaturated; Saturated

What does the egg begin to secrete upon implantation into the uterine wall?

Upon Implantation of the egg into the uterine wall, the egg begins to secrete Human Chorionic Gonadotropin (HCG), a peptide hormone which prevents the degeneration of corpus luteum, and maintains its secretion of estrogen and progesterone.

What is the path of the spermatozoa upon ejaculation?

Upon ejaculation, the mature spermatozoa are propelled through the vas deferens to the ejaculatory duct then into the urethra and then out of the penis. As the spermatozoa pass the seminal vesicles, just before the prostate, the seminal vesicles, the prostate and the bulbourethral glands (cowper's gland) all add in fluid which comprises the Semen releases upon ejaculation.

When is the female said to be pregnant?

Upon implantation of the blastocyst into the uterine wall.

Autotroph

Use CO₂ as sole source of carbon - is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple substances present in its surroundings, generally using energy from light (by photosynthesis) or inorganic chemical reactions (chemosynthesis). They are the producers in a food chain, such as plants on land or algae in water. They are able to make their own food, and do not need a living energy or carbon source. Autotrophs can reduce carbon dioxide (add hydrogen to it) to make organic compounds. The reduction of carbon dioxide, a low-energy compound, creates a store of chemical energy. Most autotrophs use water as the reducing agent, but some can use other hydrogen compounds such as hydrogen sulfide. Phototrophs, a type of autotroph, convert physical energy from sun light (in case of green plants) into chemical energy in the form of reduced carbon.

Heterotroph

Use preformed, organic molecules as their source of carbon. - is an organism that cannot fix carbon and uses organic carbon for growth.[1] This contrasts with autotrophs, such as plants and algae, which can use energy from sunlight (photoautotrophs) or inorganic compounds (lithoautotrophs) to produce organic compounds such as carbohydrates, fats, and proteins from inorganic carbon dioxide. These reduced carbon compounds can be used as an energy source by the autotroph and provide the energy in food consumed by heterotrophs.

How is the flagellum propelled?

Using the energy from a proton gradient rather than ATP.

______ lipoproteins transport triglycerides from the liver to adipose tissue.

VLDL

In active immunity, production of memory B cells against a particular antigen is conferred by _____.

Vaccination - a second vaccination a few month later is typically needed to cause a secondary response which increases the longevity of immunity for the antigen.

How are the blood levels of vasopressin and aldosterone in a dehydrated person likely to compare to those of a healthy individual?

Vasopressin and aldosterone levels are likely to be higher in a dehydrated individual. - Vasopressin/ADH increases water retention, thus ADH levels will increase in response to dehydration - Aldosterone is released form the adrenal cortex in response to low blood pressure. - In a dehydrated person, blood volume would be low, likely resulting in diminished blood pressure. Thus, aldosterone levels would rise in response to ow blood pressure, increasing sodium reabsorption.

____ always carry blood to the heart; ___ always carry blood away from the heart.

Veins; Arteries

Describe acceleration and velocity for an object traveling in a circle

Velocity is constant, but the object is constantly changing direction, therefore, the object is continually accelerating.

Deoxygenated blood coming from the body enters the heart via the ___ ___.

Vena cava

______ have myelination to increase the speed of nervous impulse transmission along the axon, while ____ do not have this.

Vertebrates have myelination to increase the speed of nervous impulse transmission along the axon, while invertebrates do not have this.

How do we class bacteria based on the type of cell wall they possess?

Via Gram Staining:

How is the chyme moved through the intestines?

Via Peristalsis

Through which duct does the lymphatic system connect to the circulatory system?

Via The thoracic duct of the lymphatic system is the largest lymphatic vessel in the body. It is also known as the left lymphatic duct, alimentary duct, chyliferous duct, and Van Hoorne's canal. - It collects most of the lymph in the body (except that from the right arm and the right side of the chest, neck and head, and lower left lobe of the lung, which is collected by the right lymphatic duct) and drains into the systemic (blood) circulation at the left brachiocephalic vein between the left subclavian and left internal jugular veins. - The thoracic duct originates in the abdomen from the confluence of the right and left lumbar trunks and the intestinal trunk, forming a significant pathway upward called the cisterna chyli. It extends vertically in the chest and curves posteriorly to the left carotid artery and left internal jugular vein at the C7 vertebral level to empty into the junction of the left subclavian vein and left jugular vein, below the clavicle, near the shoulders. It traverses the diaphragm at the aortic aperture and ascends the superior and posterior mediastinum between the descending thoracic aorta (to its left) and the azygos vein (to its right).

How is the chyme mixed with the digestive juices?

Via a second type of intestinal motion called segmentation.

How does fungi obtain their food?

Via absorption rather than ingestion: - they secrete their digestive enzymes outside their bodies and then absorb the products of digestion.

How do yeasts reproduce?

Via asexual reproduction by budding (also called cell fission), in which a smaller cell pinches off from the single parent cell

How is membrane fluidity moderated in Eukaryotic cells?

Via cholesterol

How does the action potential from the Bundle of His branch out through the ventricular walls?

Via conductive fibres called Purkinje Fibres.

How is glucose transported into most human cells?

Via facilitated diffusion

How do the amino acids, dipeptides and tripeptides enter the enterocytes?

Via facilitated or active transport. - once inside the enterocytes, intercellular enzymes convert all di- and tripeptides into amino acids. - because the chemistry of each amino acid varies greatly, each transport mechanism is specific to a few amino acids or polypeptides.

How are beta-sheets and alpha-helices strengthened?

Via hydrogen bonds between the carbonyl oxygen and the hydrogen on the amino group

How are the glucocorticoids regulated?

Via negative feedback to both the anterior pituitary and they hypothalamus.

How are proteins and large particles that cannot be taken up by the capillaries removed from the interstitium and returned to the blood?

Via the lymphatic system

Nearly all glucose is reabsorbed via which cells of the Nephron?

Via the secondary active transport proteins on the apical membranes of the proximal tubule cells.

How do molecules that are too large or too charged to passively diffuse transported across the membrane?

Via transport or carrier proteins in a process called facilitated diffusion, though in order for it to be called facilitated diffusion, diffusion must occur down the electro-chemical gradient of all species involved. No energy required

How is viral DNA/RNA inserted into Eukaryotic cells vs. Prokaryotic cells?

Viral DNA/RNA is injected into host bacterial(prok) cells via viral digestive enzymes and penetration of the cell wall via the viral tail... this process is like a hypodermic syringe-like motion Viral DNA/RNA is inserted into eukaryotic cells by being engulfed through an endocytotic process.

What is the first step in viral infection of a host cell?

Viral infection begins when a virus adsorbs to a specific glycoprotein chemical receptor site on the host cell. This is the most crucial step, because, the virus cannot infect the cell if the specific receptor is not present.

What is a mature virus outside the host cell called?

Virion

_____ are small rings of naked RNA without capsids, they only infect plants.

Viroids

What sort of NTs do viruses possess?

Viruses possess either RNA or DNA, but never both. This is unlike all living organisms that contain both at all times.

______ ___ is a precursor to all pigments in in rods and cones.

Vitmain A

What does loss of blood do urine volume?

Volume of urine produced would be greater than normal. Loss of blood would mean loss of plasma proteins, which in turn, would decrease plasma osmotic pressure. Intravenous fluids would maintain blood volume and blood pressure, but would contain no plasma proteins to oppose hydrostatic pressure. - Plasma proteins provide osmotic pressure to counteract blood pressure forcing filtrate through Bowman's capsule. - This would promote production of extra glomerular filtrate and urine even though blood pressure remained the same

Is skeletal muscle involuntary or voluntary?

Voluntary

Skeletal muscle is ____ muscle tissue.

Voluntary; wherein it can consciously controlled

What is the occurrence of distinct forms within a species called?

Polymorphism: - occurs when two or more clearly different phenotypes exist in the same population of a species - in other words, the occurrence of more than one form or morph. - these are not mutations, rather they are commonly found genetic differences.

What is it called when the product returns to activate the enzyme?

Positive feedback

What types of receptors are Post-Synaptic Receptors?

Post-synaptic receptors may be ion channels which open when their respective NTs attach, or they may act via act via second messenger system, activating another molecule inside the cell to make changes.

The ___ ____ is also known as the neurohypophysis.

Posterior Pituitary

What are the functions of the cell wall?

Prevent the protoplast from bursting. - Most bacteria are hypertonic to their environment, meaning they have more particles than the aqueous solution surrounding them. - Because of this, water outside the cell moves into the cell via osmosis. - As the cell fills with water and the hydrostatic pressure builds, it eventually equals the osmotic pressure and the filling stops. - the cell wall is strong enough to withstand these pressures. - water continues to move in and out of the cell very rapidly, but equilibrium is reached.

____ are naked proteins that cause infections in animals, they are capable of reproducing themselves, apparently without DNA or RNA.

Prions

What do progesterone and estrogen do during the secretory/luteal phase?

Progesterone and Estrogen inhibit the release of GnRH from the hypothalamus, and LH and FSH from the ant. pit; preventing the maturation of additional follicles.

When does progesterone peak and why?

Progesterone starts to peak right after ovulation because the corpus luteum secretes it.

Compare Proks to Euks:

Prokaryotes have no complex, membrane-bound organelles, all living organisms have both RNA and DNA, so proks have RNA and DNA. They translate proteins so they must have ribosome, though their sedimentation coefficients are 50S and 30S to form a 70S ribosome - Proks have no nucleus

What are Mesosomes and do prokaryotes possess them?

Prokaryotes may or may not possess mesosomes, which are invaginations of the plasma membrane. They may be involved in cell wall formation during cellular division.

What type of organism was the first to evolve on Earth?

Prokaryotes, they are at least 3.6 byo

______ stimulates the production of milk, lactation; while _____ stimulates the release of milk or ejection.

Prolactin stimulates the production of milk, lactation; while oxytocin stimulates the release of milk or ejection.

______ is a peptide hormones that promotes lactation (milk production) by the breasts.

Prolactin, PRL

Although the hypothalamus has a stimulatory effect on all the other anterior pituitary hormones; it mainly inhibits the release of ____?

Prolactin; PRL

_____ is an anterior pituitary direct peptide hormone that promotes milk production/lactation in the breasts.

Prolactin; PRL

What effects do proline residues have on protein structure?

Proline induces turns and kinks into the polypeptide that will disrupt both α-helix and β-sheet formation.

_______ are fatty acid derivative local mediators

Prostaglandins- affect smooth muscle contraction, platelet aggregation, inflammation and other reactions.

Heme is a ?

Prosthetic group

When you see nitrogen think _____!

Protein

What type of molecule begins its digestion in the stomach and via which enzyme?

Protein digestion begins in the stomach via pepsin. - The low pH of the stomach assists this process by denaturing the proteins.

Where does protein digestion begin?

Protein digestion begins in the stomach via pepsin. Proteins are hydrolyzed to polypeptides by pepsin. - in the duodenum, polypeptides are hydrolyzed to amino acids, dipeptides and tripeptides by brush border enzymes, trypsin and chymotrypsin.

Metabolism of carbohydrates and fats spare the metabolism of ____ tissue.

Protein. Fats may be used in cell membrane, as hormones, and are more efficient forms of energy than proteins.

What are most of the functional aspects of membranes due to and why?

Proteins; membrane proteins act as transporters, receptors, attachment sites, and enzymes.

_____ and _____ are two important clotting factors.

Prothrombin and fibrinogen

What is the name for the bacterial plasma membrane and everything inside of it?

Protoplast; the protoplast is not a complete bacterium, surrounding the protoplast is the bacterial envelope... one component of which is adjacent to the PM the cell wall

Most Reabsorption occurs in the ?

Proximal Tubule

Describe the Pulmonary Circulation of the blood:

Pulmonary Circulation: is the half portion of the cardiovascular system which carries oxygen-depleted blood away from the heart, to the lungs, and returns oxygenated (oxygen-rich) blood back to the heart. From the right atrium (end of systemic circulation), blood is squeezed down through the tricuspid valve and into the right ventricle. The right ventricle pumps blood up through the pulmonary valve and into the pulmonary arteries. The pulmonary arteries carry the deoxygenated blood to the arterioles and capillaries of the lungs where they become oxygenated. From the capillaries of the lungs, blood collects in the venules, then in veins, and finally in the pulmonary veins leading back to the left atrium of the heart. From the left atrium, the blood passes down through the Mitral valve and into the left ventricle.

Deoxygenated blood leaves the heart to go to the lungs via the ___ ___.

Pulmonary artery

Oxygenated blood from the lungs enters the heart via the _____ ____.

Pulmonary vein

What can be done in times of CO poisoning?

Pure oxygen is used in order to displace the CO from the hemoglobin

What happens to pyruvate once it has entered the matrix of the mitochondria?

Pyruvate is then converted to acetyl CoA in a reaction that produces NADH and CO₂.

___ - Selection involves producing large numbers of offspring that mature rapidly with little or no parental care.

R-selection

What is a main difference between RNA and DNA?

RNA is single stranded, has uracil instead of thymine, and has an additional hydroxy group.

What are the two major contributing factors to genetic change within a population?

Random mating and no selection for the fittest organism: probably do not occur in natural populations and are the most influential mechanisms of evolution.

_____ ________ endocytosis refers to the specific uptake of macromolecules such as hormones and nutrients.

Receptor mediated endocytosis; The ligand binds to a receptor protein on the cell membrane, and is then moved to a clathrin coated pit. Clathrin is a protein that forms a polymer adding structure to the underside of the coated pit. The coated pit then invaginates to form a coated vesicle. The purpose of this process, unlike that of phagocytosis, is to absorb the ligand, whereas the ligands in phagocytosis exist only to to act as signals to initiate phagocytosis of other particles.

Describe a red blood cell:

Red Blood Cells, or erythrocytes, contain the protein hemoglobin which is capable of binding and transporting oxygen.

The diameter of a capillary is equal to that of a single _____ blood cell

Red blood cell

Why is red muscle capable of longer periods of contraction?

Red muscle has large myoglobin reserves along with high amounts of mitochondria.

As electrons move within the ETC, each intermediate carrier molecule is?

Reduced by the preceding molecule (given an electron) and oxidized by the following molecule (electron is taken away)

Triacylglycerols:

Referred to as triglycerides, fats or oils. A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids.[1] There are many triglycerides: depending on the oil source, some are highly unsaturated, some less so. Constructed from a 3 carbon backbone called a glycerol which is attached to 3 fatty acids. Triglycerides, as major components of very-low-density lipoprotein (VLDL) and chylomicrons, play an important role in metabolism as energy sources and transporters of dietary fat.

What does non-Mendelain inheritance refer to?

Refers to any pattern of inheritance in which traits do not segregate in accordance with Mendel's laws (eq. genomic imprinting, mosaicism, gene conversion, etc)

_____ ______ is when specialized cells release secretory vesicles in response to a certain chemical or electrical stimulus.

Regulated Secretion

What is the period called when the membrane is hyperpolarized and making its way back to resting potential?

Relative Refractory Period; during this time, only an abnormally large second stimulus can create another AP

What stimulates the release of ACTH from the anterior pituitary?

Release of ACTH is stimulated by many types of stress. Glucocorticoids are stress hormones. - Glucocorticoids include cortisol.

When does the replication of all the oogonium take place?

Replication of all oogonium (2n) that will be developed over a lifetime takes place before birth.

What are the 2 and 3 stages, the energy acquiring stages of cellular metabolism called?

Respiration

Describe the function of the semicircular canals:

Responsible for balance. Each canal contains fluid and hair cells. When the body moves or the head position changes with respect to gravity, the momentum of the fluid is changed impacting on the hair cells, and the body senses the motion. The canals are oriented at right angles to each other, in order to detect movement in all directions.

The ____ _____ is established mainly by an equilibrium between passive diffusion of ions across the membrane and the Na⁺/K⁺ pump.

Resting Potential: - The relatively static membrane potential of quiescent cells is called the resting membrane potential (or resting voltage), as opposed to the specific dynamic electrochemical phenomena called action potential and graded membrane potential.

Individuals having genotypes that code for non-functional products of the Rh gene are said to be ?

Rh-negative; - thus, all others are Rh-positive

_______ is a protein bound to a prosthetic group called retinal which is derived from vitamin A.

Rhodopsin

The oxygen dissociation curve shifts ____ in tissues where Hb should unload bound oxygen.

Right

What are the types of cells found in the retina?

Rods and cones, named based on their characteristic shapes.

Rods have the pigment ______; while cones have?

Rods have the pigment Rhodopsin; while cones have 3 different pigments that are stimulated by a slightly different spectrum of wavelengths.

Why can rods NOT distinguish color?

Rods sense all photons with wavelengths in the visible spectrum (390 nm to 700 nm), thus they cannot distinguish colors.

What are two aspects of a compound that affect its semi-permeability?

SIze and polarity; The larger the molecule, the less permeable the membrane is to that molecule. The greater the polarity of a molecule, the less permeable the membrane to that molecule.

What are good acronyms to remember the Na⁺/K⁺ pump?

SOPI and PONI Sodium Out Potassium In or Positive Out Negative In

What may be found in the capsid of a virion?

SS DNA, SS RNA, DS RNA, DS DNA, reverse transcriptase

What role does saliva play in the movement of the bolus through the esophagus?

Saliva lubricates the food

____ _____ is the propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials without needing to increase the diameter of an axon.

Saltatory Conduction: - Because the cytoplasm of the axon is electrically conductive, and because the myelin inhibits charge leakage through the membrane, depolarization at one node of Ranvier is sufficient to elevate the voltage at a neighboring node. Thus, the voltage at the first node of Ranvier extends spatially to the next node of Ranvier. At each successive node, the membrane potential of the axon is thereby brought to the threshold potential to initiate an action potential. Ions need only to cross the axon membrane to propagate the action potential at the nodes, but not anywhere under the myelin along the axon. Thus in myelinated axons, action potentials do not propagate continuously as waves, but instead recur at successive nodes, and in effect "hop" along the axon, by which process they travel faster than they would otherwise. (The action potential only moves in one direction, because the sodium channels at the previous node of Ranvier are inactivated, and cannot regenerate another action potential, even when depolarized.) In summary, the charge will passively depolarize the adjacent node of Ranvier to threshold, triggering an action potential in this region and subsequently depolarizing the next node, and so on.

What is the smallest functional unit of skeletal muscle?

Sarcomere: - a sarcomere is composed of many strands of two protein filaments, the thick and the thin filament, laid side by side to form a cylindrical segment. - the sarcomere is composed of interdigitated strands of thick myosin and thin actin filaments. - is the basic unit of a muscle. Muscles are composed of tubular muscle cells (myocytes or myofibers). Muscle cells are composed of tubular myofibrils. Myofibrils are composed of repeating sections of sarcomeres, which appear under the microscope as dark and light bands. Sarcomeres are composed of long, fibrous proteins that slide past each other when the muscles contract and relax. Two of the important proteins are myosin, which forms the thick filament, and actin, which forms the thin filament. Myosin has a long, fibrous tail and a globular head, which binds to actin. The myosin head also binds to ATP, which is the source of energy for muscle movement. Myosin can only bind to actin when the binding sites on actin are exposed by calcium ions. Actin molecules are bound to the Z line, which forms the borders of the sarcomere. Other bands appear when the sarcomere is relaxed.[1] A muscle cell from a biceps may contain 100,000 sarcomeres.[2] The myofibrils of smooth muscle cells are not arranged into sarcomeres.

Each myofibril is also surrounded by a specialized endoplasmic reticulum called the ____ _____, the lumen of which is is filled with Ca²⁺ that stimulates muscle contraction.

Sarcoplasmic reticulum

____ ____ support ganglia, groups of cell bodies in the peripheral nervous system.

Satellite Cells: - Satellite glial cells are small cells that surround neurons in sensory, sympathetic and parasympathetic ganglia. These cells help regulate the external chemical environment. Like astrocytes, they are interconnected by gap junctions and respond to ATP by elevating intracellular concentration of calcium ions. They are highly sensitive to injury and inflammation, and appear to contribute to pathological states, such as chronic pain.

____ ____ create the myelin in the Peripheral Nervous System.

Schwann Cells: - provide myelination to axons in the peripheral nervous system (PNS). They also have phagocytotic activity and clear cellular debris that allows for regrowth of PNS neurons

Molecules that relay signals from receptors on the cell surface to target molecules inside the cell, in the cytoplasm or nucleus. They relay the signals of hormones like epinephrine (adrenaline), growth factors, and others, and cause some kind of change in the activity of the cell. They greatly amplify the strength of the signal. ______ ______ are a component of signal transduction cascades

Secondary Messenger Systems

How is water reabsorbed in the Proximal tubule?

Water is reabsorbed into the renal interstitium of the proximal tubules across relatively permeable tight junctions due to the favourable osmotic gradient. - thus some solutes that are not actively reabsorbed are reabsorbed by passive or facilitated diffusion.

Is the fate of a fully differentiated cell able to be altered at all?

Yes, under proper conditions, even the fate of a fully differentiated cell can be altered.

What happens when an antibody whose base is bound to a mast cell also binds to an antigen?

When an antibody, whose base is bound to a mast cell, also binds an antigen, the mast cell releases histamine and other chemicals.

What is it called when an ovum and a spermatozoa join?

Zygote

What is secondary active transport?

Secondary active transport or co-transport, uses energy to transport molecules across a membrane. In contrast to primary active transport, there is no direct coupling of ATP; instead, the electrochemical potential difference created by pumping ions out of the cell is used. The two main forms of this are antiport and symport. 1) Antiport:In antiport two species of ion or other solutes are pumped in opposite directions across a membrane. 2) Symport: Symport uses the downhill movement of one solute species from high to low concentration to move another molecule uphill from low concentration to high concentration (against its electrochemical gradient). The two species move in the same direction across the membrane.

List the things secreted from the proximal tubule and the things reabsorbed by it:

Secreted: Drugs, toxins, ammonia, uric acid, bile pigments, H⁺ ions. Reabsorbed: H₂0, K⁺, HCO⁻₃, Na⁺, Cl⁻, Glucose, Nutrients

What are the peptide hormones secreted by the small intestine after a meal and what are their roles?

Secretin, Cholecystokinin and gastric inhibitory peptide all increase insulin levels especially in the presence of glucose.

Both _____ and ______ occur in the proximal tubule.

Secretion and reabsorption.

_____ _______ may contain enzymes, growth factors, or extracellular matrix components. They release their contents via exocytosis.

Secretory vesicles

______ or _____ neurons receive signals from a receptor cell that interacts with its environment. This neuron then transfers this signal to other neurons.

Sensory or afferent neurons; travel towards the CNS - 99% of sensory input is discarded by the brain

Sensory receptors transduce ______ stimulus to ____ signals.

Sensory receptors transduce physical stimulus to neural signals.

_____ neurons are are located dorsally (toward back) from the spinal cord, while ____ neurons are located ventrally (toward front) of the spinal cord.

Sensory; Motor. - sensory neurons enter the spinal cord via the dorsal root ganglion then dorsal horn, while motor neurons leave the spinal cord via the ventral horn.

What are the 6 polar amino acids?

Serine, threonine, cysteine, tyrosine, asparagine and glutamine

What is plasma called once the clotting factor fibrinogen has been removed?

Serum

What are the major functions of phospholipids?

Serve as structural component of the cell membrane

Using Newton's Universal Gravitational Law, how would you determine how fast two bodies accelerate towards each other?

Set F₁=F₂ =m₁a₁=m₂a₂ Thus, if m₁ is twice as massive as m₂: =2a₁=a₂

A hollow, protein tube that connects two bacteria to allow the passage of DNA

Sex pilus

What is a gene called when it is found on the sex-chromosome or 23rd pair of chromosomes?

Sex-linked chromosomes.

Hemophilia is a ____-linked disease.

Sex-linked. - Sex linkage is the phenotypic expression of an allele related to the chromosomal sex of the individual. This mode of inheritance is in contrast to the inheritance of traits on autosomal chromosomes, where both sexes have the same probability of inheritance. Since humans have many more genes on the X than the Y, there are many more X-linked traits than Y-linked traits. - X-linked recessive traits are expressed in all heterogametics (males), but are only expressed in those homogametics (females) that are homozygous for the recessive allele. For example, an X-linked recessive allele in humans causes hemophilia. Hemophilia is much more common in males than females because males are hemizygous - they only have one copy of the gene in question - and therefore express the trait when they inherit one mutant allele. In contrast, a female must inherit two mutant alleles, a less frequent event since the mutant allele is rare in the population.

Describe the shape and composition of short bones:

Short bones are cuboidal. - they are ankle and wrist bones.

What effect does ADH have on blood pressure?

Since ADH causes water to be reabsorbed into the blood from the renal collecting ducts, it increases the amount of water in the blood, thereby increasing overall blood pressure.

How can you determine the spring constant k for a spring attached to the ceiling with a mass, m attached?

Since F on the spring would simply be Fn=mg, then the spring constant can be found by replacing F with mg: k=mg/∆x

How do bacteria create genetically different individuals? In other words, what are the forms of bacterial genetic recombination?

Since bacteria do not undergo sexual reproduction, meiosis or mitosis, they use conjugation, transformation and transduction.

When does estrogen peak?

Since both FSH and LH peaks are caused by the peak of estrogen, estrogen peaks immediately before both. It also peaks again after ovulation because of the corpus luteu.

What are Barr Bodies?

Since females have two X chromosomes, her genotype is found through the normal rules of dominance. However, in most somatic cells, one of the X chromosomes will condense, and most of its genes will become inactive. The tiny dark object formed is called a Barr Body. Barr bodies are formed at random, so the active allele is split about evenly among the cells. This is known as the Lyon Hypothesis. - thus, in most cases the recessive phenotype is only displayed in homozygous recessive individuals. - thus, the female may carry a recessive trait on her 23rd pair of chromosomes without expressing it. If she does express it, she is said to be a carrier for that trait. Such a trait has a strong chance of being expressed in her offspring, regardless of the genotype of her mate.

Where does mitosis take place in fungal cells?

Since fungi have no centrioles, mitosis takes place entirely in the nucleus; the nuclear envelope never breaks down.

What is the net ATP production from fermentation?

Since in fermentation, NADH is restored back to NAD+, 2 ATP are formed.

Since microtubules are found in cilia, what might a problem in microtubule production result in?

Since microtubules are part of cilia and cilia exist in the respiratory tract, fallopian tubes and ependymal cells of the spinal cord, a problem in microtubule production may result in a problem breathing, fertility or circulation of CSF.

Why is that secretory vesicles act as the vehicle with which to supply the cell membrane with its integral proteins and lipids and as the mechanism for membrane expansion?

Since secretory vesicles excrete contents from the cell via exocytosis, the secretory vesicles fuse with the membrane and add its membrane components to that of the cell membrane.

What happens to the velocity and acceleration of a ball as it rolls down a curved slope?

Since the acceleration is gsinθ, and θ is constantly decreasing and so is the sin of θ, the acceleration is decreasing. Since there is some acceleration through the drop, the velocity is increasing. Acceleration decreases from 10m/s² to fractions of g based on sinθ, because the angle to the ground is constantly getting smaller.

How do thyroid hormones travel in the blood and why?

Since thyroid hormones are lipid soluble, they must travel in the blood with a plasma protein transporter molecule to prevent coagulation of the hormones. - the thyroid hormones are slowly released to their target tissues and bind to receptors inside the nucleus.

Crossing over during prophase I can be classified as either a ____ crossover or a ____ crossover.

Single or double crossovers

Explain how muscle attaches one bone to another:

Skeletal muscle connects one bone to another. The muscle does not attach directly to the bone, but instead is attached via a tendon. - Ligaments connect bone to other bone - Typically, a muscle stretches across a joint - The muscle origin is on the larger bone, which remains relatively stationary, and its insertion is on the smaller bone, which moves relative to the larger bone upon contraction of the muscle.

Why are Slow twitch type I muscle fibres red?

Slow twitch type I muscle fibres are red from large amounts of myoglobin. - myoglobin is an oxygen storing protein similar to hemoglobin, but having only one protein subunit. - myoglobin stores oxygen in muscle cells.

Substrates are generally _____ than the enzyme.

Smaller

What are the 3 parts of the small intestine from smallest to largest?

Smallest- Duodenum Medium- Jejunum Largest- Ileum

______ ER is the site of lipid synthesis, including steroids.

Smooth ER;

The endoplasmic reticulum which lacks ribosomes is called the _____ _____ _____.

Smooth Endoplasmic reticulum or the agranular ER.

What type of muscle performs the peristaltic action?

Smooth muscle

Do smooth muscle cells contain thick and thin filaments? and if so, are they organized into sarcomeres?

Smooth muscle cells do contain thick and thin filaments but they are not organized into sarcomeres. Smooth muscle cells also contain intermediate filaments, which are attached to dense bodies spread throughout the cell.

Does smooth muscle require calcium to contract and if so why?

Smooth muscle contain thin and thick filaments (actin and myosin), thus it does require calcium to contract.

Smooth muscle is mainly ______, so it is innervated by the ____ NS.

Smooth muscle is mainly involuntary, so it is innervated by the autonomic NS.

What types of stimuli does smooth muscle respond to?

Smooth muscle responds to neural stimuli, hormones, changes in pH, O₂ and CO₂ levels, temperature, and ion concentrations

The ____ NS innervates skeletal muscle and is voluntary.

Somatic

Where do somatic motor neurons synapse and which NT do they use?

Somatic Motor Neurons synapse directly on their effectors and use acetylcholine as their NT. - the motor functions of the somatic NS can be consciously controlled and are voluntary.

The _____ NS is designed primarily to respond to the external environment. It contains both sensory and motor functions. Its motor neurons innervate only skeletal muscle.

Somatic NS

Pancreatic ________ leads to both decreased insulin and glucagon levels.

Somatostatin

_______ inhibits both glucagon and insulin.

Somatostatin

Which hormone is released by the δ-cells of the pancreas and acts to inhibit both insulin and glucagon?

Somatostatin; the role of somatostatin is to extend the period of time over which nutrients are absorbed.

What is Nitrogen Fixation?

Some bacteria are capable of fixing N₂; therefore Nitrogen fixation is the process by which N₂ is converted to ammonia. The next step is performed by yet another bacteria, called Nitrification, wherein ammonia is converted into nitrates, which are useful for plants.

Describe how reversible covalent modification regulates enzymes:

Some enzymes are activated or deactivated by phosphorylation or by the addition of some other modifier such as AMP. The removal of the modifier is almost always accomplished by hydrolysis. Phosphorylation typically occurs in the presence of a protein kinase.

How does bone also serve as a storage site for Ca²⁺ and HPO₄²⁻?

Some of the body's Ca²⁺ exists in bone in the form of slightly soluble calcium salts such as CaHPO₄. It is these salts that buffer the plasma Ca²⁺ levels. Thus, bone acts as a storage site for Ca²⁺ and HPO₄²⁻.

What are goblet cells and where are they located?

Some of the epithelial cells of the villi/small intestine are goblet cells that secrete mucous to lubricate the intestine and help protect the brush border from mechanical and chemical damage. These would be like the mucous cells of the stomach

What can occur if the sex pilus is made while the F plasmid is integrated into the chromosome?

Some or all of the rest of the chromosome may be replicated and transferred to the other bacterium

_____ is the process by which new species are formed?

Speciation

____ is the key process in evolution.

Speciation: - when a single ancestral species splits into multiple new species or a single species evolves into a reproductively distinct new species.

What is the process of sperm production called and where does it take place?

Sperm production is called Spermatogenesis and it takes place in the seminiferous tubules of the testes.

What are sperm produced from?

Spermatogonia located in the seminiferous tubules arise from epithelial tissue to become spermatocytes, spermatids, and then spermatozoa.

A _______ is a ring of muscle that is normally contracted so that there is no opening at its center.

Sphincter

What are spike proteins?

Spike proteins, encoded from the viral nucleic acids, protrude from the new viral envelope (envelope is borrowed from the host cell). These spike proteins bind to receptors on new host cells causing the virus to be infectious. It is the spike proteins that human antibodies recognize when fighting the viral infection.

In which parts of bone is spongy bone found?

Spongy bone is typically found at the Metaphysis and Epiphysis of bone... thus at the bulbar ends of bones

How long to RBCs survive?

Squeezing through capillaries wears down their plasma membranes in about 120 days.

_____ is a straight chain of glucose molecules.

Starch

What is the Fluid Mosaic Model?

States that the membrane is fluid, because all forces holding the entire membrane together are intermolecular, its parts can move laterally but cannot separate.

Where are the Keratinocytes produced and what happens to them as they rise to the top of the epidermis?

Stem cells in the deepest layer of the epidermis continually divide to produce keratinocytes and other cells. - Keratinocytes are pushed to the top layer - as they rise, they accumulate keratin and die, losing their cytoplasm, nucleus, and other organelles. - When the cell reaches the outermost layer of the skin, they slough off of the body. - this process takes 2-4 weeks.

No absorption takes place in the ____?

Stomach

Protein digestion begins in the _____?

Stomach

The ____ is a very flexible pouch that both mixes and stores food, reducing it to a semifluid mass called Chyme.

Stomach

What stimulates the release of glucocorticoids?

Stress stimulates the release of ACTH from the ant.pit, which then stimulates the adrenal cortex to synthesize and release glucocorticoids (cortisol), which are developed for prolonged stress responses.

Why would cardiac output not be dependent on stroke volume differences between the right and left ventricles?

Stroke volume of the ventricles must be the same or we'd have a never ending back-log of blood in one or the other circulations, ending with the faster circulation running dry. Thus, both halves of the circulation must pump the same quantity of blood with each stroke

Collagen is a ____ protein.

Structural

What do structural proteins provide for the ECM?

Structure with strength. Most common structural proteins is collagen.

What does the control over a reaction due to the use of enzymes allow for?

Such extreme control over the reaction rates gives enzymes the ability to pick and choose which reactions will or will not occur inside the cell.

What are the major carbohydrates in the human diet?

Sucrose, lactose, and starch.

_____ and _____ are disaccharides made from glucose and fructose, and from glucose and galactose, respectively.

Sucrose= glucose +fructose Lactose= glucose + galactose

Where are Sudoriferous glands found and what are they?

Sudoriferous glands are sweat glands and they are found in the skin separate from hair follicles.

____ T cells play a negative feedback role in the immune system.

Suppressor T cells

What coats each alveolus and what is its purpose?

Surfactant coats each alveolus and it lowers the surface tension of the alveoli in order to facilitate gas exchange across the membrane

A ____ is a relationship between two species.

Symbiosis

Secretory cells of the adrenal medulla are part of the ________ Nervous System.

Sympathetic

Secretory cells of the adrenal medulla secrete Epinephrine and Norepinephrine as part of the ______ nervous system?

Sympathetic

The NTs used by the short pre-ganglionic neurons and by the long post-ganglionic neurons of the sympathetic NS are?

Sympathetic NS: - NT for the short pre-ganglionic neurons is acetlylcholine - NT for the long post-ganglionic neurons is adrenaline/noradrenaline/epinephrine or norepinephrine

Which nervous system innervates the smooth muscle wrapping arteries?

Sympathetic Nervous System

_____ signals originate in neurons whose cell bodies are found in the spinal cord, while ______ signals originate in neurons whose cell bodies are found in both the brain and spinal cord.

Sympathetic signals originate in neurons whose cell bodies are found in the spinal cord, while parasympathetic signals originate in neurons whose cell bodies are found in both the brain and spinal cord.

What are synergistic muscles?

Synergistic muscles assist the agonist by stabilizing the origin bone or by positioning the insertion bone during the movement. In this way skeletal muscles allow for movement and posture.

What are synergistic muscles?

Synergistic muscles assist the agonist by stabilizing the origin bone or by positioning the insertion bone during the movement. In this way, skeletal muscle allows for posture and movement.

What is the purpose of the synovial fluid within synovial joint capsules?

Synovial fluid provides lubrication and nourishment to the cartilage. - The synovial fluid contains phagocytotic cells that remove microbes and particles which result from wear and tear from joint movement. - Synovial joints allow for a wide range of movement.

______ joints are not bound by the intervening cartilage. Instead, they are separated by a capsule filled with _____ fluid.

Synovial joints are not bound by the intervening cartilage. Instead, they are separated by a capsule filled with synovial fluid.

What is a lyase that catalyses addition of one substrate to a double bond of a second substrate called?

Synthase ATP synthase

What is the circulatory path of the blood? Describe the systemic circulatory part:

Systemic: the part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart. Beginning with the left ventricle, blood up through the aortic valve, through the aorta. From the aorta, branch many smaller arteries, which themselves branch into smaller arterioles, which branch into still smaller capillaries. Blood from the capillaries collected into venules, which themselves collect into larger veins, which collect again into the superior and inferior vena cava. The vena cava empty into the Right Atrium of the heart.

Blood pressure varies between ____ and ____ pressures for each heartbeat.

Systolic and diastolic

____ is "peak presure" in the arteries, which occurs near the end of the cardiac cycle when the ventricles are contracting.

Systolic pressure= peak arterial pressure

What are T Lymphocytes?

T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells (NK cells), by the presence of a T cell receptor (TCR) on the cell surface. They are called T cells because they mature in the thymus. There are several subsets of T cells, each with a distinct function.

What do T-Tubules allow for?

T- Tubules allow for a uniform contraction of the muscle by allowing the action potential to spread through the muscle cell more rapidly. - A T-tubule (or transverse tubule) is a deep invagination of the sarcolemma, which is the plasma membrane, only found in skeletal and cardiac muscle cells. These invaginations allow depolarization of the membrane to quickly penetrate to the interior of the cell.

Through which tunnels does an AP move deep into the muscle cell?

T- tubules

What are the 2 states that hemoglobin can exist in?

T-State: tense state, No oxygen O₂ bound R-State: relaxed state, O₂ is bound

Where do T-cells mature into T-Lymphocytes?

T-cells migrate to and mature in the thymus.

What are T-tubules?

T-tubules are deep invaginations of the sarcolemma, allowing for the spread of an AP.

How do T3 and T4 concentrations affect TSH release from the anterior pituitary?

T3 and T4 concentrations have a negative feedback effect on TSH releases, both at the anterior pituitary and the hypothalamus. The T3 and T4 hormones will travel to the hypothalamus and ant. pit. in order to shut down release of TRH and TSH, respectively.

What is the main difference between T3 and T4?

T3 contains 3 iodine atoms, T4 contains four.

What is the difference between T3 and T4?

T3 has 3 iodine atoms where T4 has 4.

What would tension in a rope be equal to if a mass, m, was hanging from the ceiling?

T=mg

_____ connect muscle to bone

Tendons

Tendons connect ____ to _____?

Tendons connect muscle to bone.

What does the Urey-Miller Experiment demonstrate?

That life may have evolved from inorganic precursors

How do you remember the path of the spermatozoa during the entire process of production to ejaculation?

The "seven up" mnemonic: Seminiferous tubules→Epididymis→Vas deferens→Ejaculatory duct→nothing→urethra→penis

When does speciation begin?

When gene flow ceases between two sections of a population, speciation begins.

What distinguishes a cosubstrate from a regular substrate?

The Cosubstrates reversibly bind to a specific enzyme, and transfer some chemical group to another substrate. It is then reverted to its original form by another enzymatic reaction. This reversion of the cosubstrate to its original form is what distinguishes a cosubstrate from normal substrates. Prosthetic groups, on the other hand, remain covalently bound to the enzyme through out the reaction, and, like the enzyme, emerge from the reaction unchanged.

What is the name of the shaft of a typical long bone?

The Diaphysis

What does the ECM provide?

The ECM may provide structural support, help determine cell shape and motility, and affect cell growth.

How would you determine the Fc of an object being swirled around in a circle on a string?

The Fc is created by the tension in the string, therefore the Fc=T. Whenever there is a centripetal force, there is a force causing it.

What roles does the Haldane Effect play in oxygen transport?

The Haldane Effect facilitates the transfer of CO₂ from blood to lungs, and from tissues to blood. - Reduced Hb (Hb without oxygen) acts as a blood buffer by accepting protons. - It is the greater capacity of reduced Hb to form carbamino Hb that explains the Haldane Effect.

What is the space between both pleura called?

The Intrapleural space or pleural cavity

The _______ ______ monitors filtrate pressure in the ____ _____.

The Juxtaglomerular apparatus monitors filtrate pressure in the distal tubule.

How do the Killer T cells or also known as the Cytotoxic T cells kill infected cells?

The Killer/Cytotoxic T cell binds to the antigen-carrying cell and it releases perforin onto the antigen-carrying cell in order to perforate and lyse the infected cell.

Why is it that Killer/Cytotoxic T cells have the ability to attack many cells, unlike a macrophage which can only attack a finite number of cells?

The Killer/Cytotoxic T cells have the ability to attack many cells because they do not phagocytize their victims, they bind to and perforate their victims with perforin.

What is the role of the lymphatic system?

The Lymphatic System recycles the interstitial fluid and monitors the blood for infection. - it also reroutes low soluble fat digestates around the small capillaries of the intestine and into the large veins of the neck.

Describe what the Michaelis Constant is and how it is derived:

The Michaelis Constant (Km) is the substrate concentration at which the reaction rate is equal to 1/2Vmax. Km does NOT vary with enzyme concentration

Describe how the NT elicits a response in the post synaptic membrane and what happens to the NT immediately after:

The NT attaches to its receptor for only a fraction of a second, and is released back into the synaptic cleft. - If the NT remains in the synaptic cleft, the post-synaptic membrane may be stimulated over and over. - In order to deal with this problem, the cell may either: 1) Destroy the NT with an enzyme in the matrix of the synaptic cleft and have its parts recycled by the presynaptic cell, or 2) The NT may diffuse out of the synaptic cleft.

What is the functional unit of the kidney?

The Nephron: is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine. A nephron eliminates wastes from the body, regulates blood volume and blood pressure, controls levels of electrolytes and metabolites, and regulates blood pH. Its functions are vital to life and are regulated by the endocrine system by hormones such as antidiuretic hormone, aldosterone, and parathyroid hormone. - each kidney has approx. 1 million nephron units.

What is the force of the inclined plane, pushing back against the gravitational force called?

The Normal Force, Fn. The normal force is always perpendicular to the surface that applies it.

What is the first time the immune system is exposed to an antigen known as?

The Primary Response

In which part of the nephron does most of the reabsorption take place and via which mechanism?

The Proximal Convoluted Tubule - secondary active transport proteins in the apical membranes of the proximal tubule cells are responsible for the reabsorption of nearly all glucose, most proteins and other solutes.

What is the structure of the Nephron?

The Proximal and Distal tubules, along with the renal corpuscle and the thick limbs of the ascending and descending loop of Henle are all located in the cortex of the kidney. - The loop of Henle and the collecting duct are located in the medulla.

What is a Punnett Square?

The Punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment.

What role do the Purkinje Fibres play in the heart?

The Purkinje Fibres in the ventricles allow for a more unified and stronger contraction.

Describe the RER:

The RER has ribosomes attached to its cytosolic side, and it synthesizes virtually all proteins not used in the cytosol. Proteins synthesized in the RER are pushed into the ER lumen and sent to the golgi.

Why is the Rh factor such a concern for mothers?

The Rh factor is a concern for mothers who are Rh- and have an Rh+ fetus, where the Rh+ antigen was inherited paternally (from father). - For the first pregnancy, the mother is not exposed to fetal blood until giving birth and problems are rare. - Upon exposure to the child's Rh+ blood, the mother develops and immune response against the Rh+ blood. These develop into Memory anti-Rh+ cells that produce the Rh+ antibodies - therefore, in a second pregnancy, if the fetus is Rh+, it may be attacked by the mother's antibodies, which are small enough to pass the placental barrier. - the problem is life threatening, because the memory anti Rh + antibodies from the mother will cross the placenta and destroy the fetal red blood cells. - this is called Erythroblastosis fetalis

What secretes inhibin and what does inhinin do?

The Sertoli cells of the testes also secrete inhibin. - Inhibin, a peptide hormone, acts on the anterior pituitary to inhibit FSH secretion. Thus, there would be inhibition of the nurture of the spermatocytes and spermatids via the sertoli cells.

What are the specialized group of cardiac muscle cells called that automatically pace the heart contractions, and where are they located?

The Sinoatrial Node (SA Node) or pace-maker cells, located in the right atrium, are responsible for initiating and spreading an action potential for heart contraction. - these cells are autorhythmic (contracts by themselves at regular intervals), spreading its signals to the surrounding cardiac cells via electrical synapses made from gap junctions.

The Sympathetic ANS deals with ___ or ___ responses, and would have what effects on the body?

The Sympathetic ANS deals with fight or flight responses: - It would increase heart rate and stroke volume; - constricts blood vessels around digestive and excretory systems, in order to increase blood flow to skeletal muscles.

What are the Tyrosine derivative hormones and where are they synthesized?

The Tyrosine derivative hormones are lipid soluble hormones derived from the amino acid tyrosine. They are synthesized in the cytosol or RER of the cell, carried through the blood by plasma proteins, and cross directly through a plasma and nuclear membrane to influence gene expression.

Which is the most important nerve concerning the heart?

The Vagus nerve, which is parasympathetic, innervates both the heart and the digestive tract. The vagus nerve slows the rate heart contractions at the SA Node and increases digestive activity in the intestines.

Explain why the allele that is carried on the X-chromosome in males is expressed whether it is recessive or dominant.

The Y chromosome does not carry the allele for the sex-linked trait; thus, the allele that is carried by the X-chromosome in the male is expressed whether it is dominant or recessive.

What do the Z band and M line represent within muscle tissue?

The Z band marks the borders of sarcomere units within a myofibril and the M line represents the closest distance that two actin filaments can be relative to one another during contraction.

What do all organisms require in order to grow?

The ability to acquire carbon, energy and electrons (usually from hydrogen).

Why would a doctor feed a patient suffering from severe diarrhea an electrolyte solution with glucose in it?

The absorption of glucose increases the uptake of electrolytes like sodium. - this occurs because glucose is absorbed in a symport mechanism with sodium

What would the acceleration of an object be if the net total of all forces acting on it is zero?

The acceleration is zero.

What does the act of suckling do to the hypothalamus and menstrual cycle?

The act of suckling stimulates the hypothalamus to stimulate the anterior pituitary to release prolactin and also inhibits the menstrual cycle. Suckling stimulates release of prolactin from ant.pit. Suckling inhibits the menstrual cycle.

Describe how the SA Node/Pacemaker cells cause the contractions of the heart and the path of the action potential through the heart:

The action potential generated by the SA node causes both atria to contract so blood can be pumped into the ventricles while the atria is refilled (part of diastole). The AP produced by the SA Node spreads around both atria in order to contract both of them at the same time. - the action potential then spreads to the Atrioventricular Node (AV Node), located directly above the right ventricle. - The AV Node is slower to contract, creating a delay to allow the atria and ventricles to finish filling with blood. - From the AV Node, the action potential spreads into the Bundle of His and branches off into Purkinje Fibres which allow for a unified and strong contraction of the ventricles (systole) - the signal spreads down the atria to squeeze blood from the atria into the ventricles.

What is the specific target tissue of adrenocorticotropic hormone (ACTH)?

The adrenal cortex

What are the two parts of the adrenal gland and where are they located relative to each other?

The adrenal cortex is the outside portion of the gland, while the adrenal medulla is the inside portion.

What types of hormones are secreted from the Adrenal Cortex and what are they called?

The adrenal cortex secretes only the steroid hormones: 1- Mineralcorticoids: Aldosterone 2- Glucocorticoids: Cortisol

What are the glands called that are located on top of the kidneys?

The adrenal glands

What type of hormones are synthesized/secreted from the adrenal medulla and what are they called?

The adrenal medulla secretes catecholamines which are tyrosine derivative hormones. The important catecholamines are epinephrine and norepinephrine, or adrenaline and noradrenaline respectively.

Since muscles work in groups, what is the agonist and the antagonist?

The agonist is the muscle responsible for movement, so when it contracts, the antagonist, which is the muscle that opposes the agonist, stretches. - when the antagonist contracts, the bone moves in the opposite direction, stretching the agonist. - an example is the biceps and triceps

What is the purpose of the alveoli?

The alveoli increase overall surface area for gas exchange with the pulmonary capillary beds

How does the body distinguish between different types of sensory stimuli?

The body contains somatic sensory neurons that transfer signals from the external environment to the brain, though they are incapable of distinguishing between different types of stimuli, and are not designed to be initial receptors of such signals. Therefore, the body contains 5 types of sensory receptors, each of which responds strongly to its own type of stimulus and weakly or not at all to other types of stimuli. Each type of receptor has its own neural pathway and termination point in the CNS which results in the various sensations.

How would the body compensate for acidosis (too much acid in the blood)?

The body would increase breathing rate thereby expelling CO₂ and raising the pH of the blood. By expelling CO₂ and H₂O, the body has effectively lowered concentrations of blood H⁺ ions and H₂CO₃, effectively lowering acidity of the blood.

Where does the bolus travel from the mouth and what is this action called?

The bolus moves from the mouth into the esophagus via swallowing, and then to the stomach via peristaltic action.

What happens when the antagonist contracts and the agonist stretches?

The bone moves in the opposite direction. - An example of antagonistic muscles are the muscles of the upper arm; the bicep and triceps.

What is the role of the brush border?

The brush border contains all the membrane bound digestive enzymes, such as the carbohydrate-digesting enzymes; dextrinase, maltase, sucrase and; lactase; protein-digesting enzymes called peptidases; and nucleotide-digesting enzymes called nucleosidases.

Fatty Acids:

The building blocks for most, but not all, complex lipids. They are long chains of carbons truncated at one end by a carboxylic acid. There is usually an even number of carbons, with the max being 24. Can be saturated or unsaturated

Where are the cell bodies of somatic motor neurons located?

The cell bodies of somatic motor neurons are located in the ventral horns of the spinal cord.

What happens to glucose once in the body?

The cell oxidizes glucose, transferring its energy to the more readily useable form of ATP.

What happens if a cell is fired too often, up to several hundred times per second for several minutes?

The cell will not be able to replenish its supply of NT vesicles, and the result is fatigue- the impulse will not pass to the post-synaptic neuron.

What is the next step with the 8 cells of the morula?

The cells of the morula continue to divide for 4 days forming a hollow ball filled with fluid. This fluid filled ball is called a blastocyst.

What happens to the amino acids as they enter body cells?

The cells quickly create proteins from the amino acids so that the intracellular amino acid concentration remains low, thus ensuring that more amino acids are able to enter the cell.

The ____ NS consists of the spinal cord, the lower brain, and all of the higher brain.

The central nervous system.

Centre of Gravity:

The centre of gravity of an object is the single point at which, for the purposes of a simple mechanics problem, the force of gravity can be applied to the entire mass. If gravity is the only force, the result will be the same regardless of the orientation of that mass. The centre of mass and the centre of gravity will always coincide.

Where does the centre of mass reside in a system that is not uniformly dense?

The centre of mass is located toward the denser side from its geometric centre

What is the function of the cerebral cortex?

The cerebral cortex is incapable of functioning without the lower brain. It acts to store memories and process thoughts

What does the higher brain or cortical brain consist of?

The cerebrum or cerebral cortex.

What role does the cilia within the nasal cavity play?

The cilia moves the mucous and dust back toward the pharynx, so that it may be removed by spitting or swallowing.

What role do the cilia lining the inside of the fallopian tube play?

The cilia sweep the egg toward the uterus.

The cochlea ______ while the semicircular canals?

The cochlea detects sound, while the semicircular canals detect orientation and movement of the head.

Describe the movement of a sound wave through the cochlea:

The cochlea detects sound. The soundwave moves through the cochlea to the centre of the spiral, and then spirals back out along the scala tympani to the round window. As the wave moves through the cochlea, the alternating increase and decrease in pressure moves the vestibular membrane in and out. This movement is detected by the hair cells of the organ of corti and transduced into neural signals, which are sent to the brain. The hair cells do not actually contain hair, but contain instead a specialized microvilli called stereocilia, which detect movement.

The collecting duct is _______ to water, but it is sensitive to ____.

The collecting duct is impermeable to water, but it is sensitive to ADH.

What is the Iris?

The colored portion of the eye that creates the opening called the pupil. The iris is made from circular and radial muscles.

How is the releases of GnRH from the hypothalamus inhibited?

The combination of estrogen with progesterone from the corpus luteum inhibits the release of GnRH from the hypothalamus. Estrogen + progesterone together inhibit the release of both FSH and LH from the anterior pituitary by inhibiting the release of GnRH from the hypothalamus.

What happens to the concentration of solutes as we move from cortex to medulla?

The concentration of solutes in the interstitial fluid increases.

What does the contraction of skeletal muscle do to lymph and blood vessels?

The contraction of skeletal muscle squeezes blood and lymph vessels aiding circulation

How does contraction of skeletal muscle aid in circulation?

The contraction of skeletal muscles squeezes blood and lymphatic vessels, aiding in the circulation of blood and lymph.

What is the first part of the eye that light hits?

The corneal Epithelium which is a very thin, protective layer over the Cornea. - The cornea is non-vascular and made largely from collagen. - It is clear and has a refractive index of 1.4 which means that the most bending of light actually occurs at the interface of the air and the cornea and not at the lens.

What does the Corpus Luteum do?

The corpus luteum secretes estradiol and progesterone through out pregnancy, or, in the case of no pregnancy, for about 2 weeks until the corpus luteum degrades into the corpus albicans.

What happens if the ovum is not fertilized within the first 24 hours after ovulation?

The corpus luteum will degenerate towards the end of the secretory phase, leading to decreased progesterone levels... These decreased progesterone levels cause the endometrium to slough off, giving rise to menses (menstrual flow). - The subsequent drop in both progesterone and estrogen no longer inhibits GnRH from the hypothalamus, which re-stimulates the release of LH and FSH from the ant. pit. to begin another cycle.

Compare the cross sectional area of capillaries to that of arteries and veins:

The cross sectional area of capillaries is is far greater than that of arteries or veins.

Compare the cross-sectional area of veins and arteries:

The cross-sectional area of veins is about 4 times that of arteries.

What can the inside of the cell be divided into?

The cytosol and the ER lumen

What happens when a dendrite receives a signal?

The cytosol of the cell body is highly conductive and any electrical stimulus creates a disturbance in the electric field that is transferred immediately to the axon hillock. If the stimulus is great enough, the axon hillock generates an action potential in all directions, including down the axon. The membrane of the cell body does not contain enough ion channels to sustain an action potential. The axon, however, carries the acton potential to a synapse, which passes the signal to another cell.

What happens to the dead epithelial cells of the small intestine?

The dead cells regularly slough off into the lumen of the intestine and are replaced by new cells.

Describe how the JGA and Distal tubules control blood pressure and volume via the release of renin from the granular cells of the JGA?

When the JGA senses low sodium in the blood it releases renin from its granular cells. - Renin initiates a regulatory cascade producing angiotensin I, II and III, which ultimately stimulates the adrenal cortex to secrete aldosterone. - Aldosterone acts on the distal tubules and collecting ducts to stimulate the formation of membrane bound proteins that reabsorb sodium and secrete potassium. - this increases blood pressure, volume and osmolarity.

How does a cell in the lysogenic cycle become active and enter the lytic cycle?

The dormant virus may become active when the host cell is under some type of stress. UV light or carcinogens also may activate the virus. When the virus becomes active it becomes virulent

What were the earliest organisms and when did they originate?

The early organisms were probably heterotrophs subsisting on preformed organic compounds in their immediate surroundings. - Fossils of these organisms have been dated at 3.6 billion years old. - as preformed compounds became scarce, some of these organisms developed chemosynthetic autotrophy followed by photosynthetic autotrophy

What will the ectodermal cells develop into?

The ectodermal cells develop into the outer coverings of the body, such as the outer layers of skin, nails, and tooth enamel, and into the the cells of the nervous system and sense organs. - the ectoderm emerges first and forms from the outer layer of germ cells. - It also forms the lining of mouth, anus, nostrils, sweat glands, hair and nails. - becomes the integument, lens of the eyes, and nervous system.

Describe the effect of the catecholamines (epinephrine and norepinephrine) on the body:

The effects of E and NE on their target tissues are similar to their effects in the sympathetic nervous system, but they last much longer. - E and NE are vasoconstrictors (constrict blood vessels) of most internal organs and skin, but are vasodilators of skeletal muscle (they increase blood flow); this is consistent with the "fight-or-flight" response of these hormones.

How are the effects of the endocrine system compared to those of the nervous system and its NTs?

The effects of the endocrine system tend to be slower, less direct, and longer lasting than those of the nervous system. Endocrine hormones may take anywhere from seconds to days to exert their effects. They do not move directly to their target tissue, they are released into general circulation.

Why do people have a hard time focusing on nearby objects as they age?

The elasticity of the lens decreases with age.

What do the endodermal cells develop into?

The endodermal cells develop into the lining of the digestive tract, and into much of the liver and pancreas. - epithelial linings of the digestive/respiratory tracts, parts of the liver, pancreas, thyroid, and bladder

What does the entry of the sperm cause in the ovum?

The entry of the sperm causes the Cortical Reaction, which prevents other sperms from fertilizing the same egg. - Now the oocyte goes through the second meiotic division (equational division) to become an ovum and releases a second polar body.

What happens when the sperm makes contact with the egg?

The enzymes of the acrosome are released, they then digest a path for the sperm through the granulosa cells and the zona pellucida. The tube-like processes via which the sperm enters the oocyte, are called acrosomal processes. - the cell membranes of the sperm and the oocyte fuse upon contact, and the sperm nucleus enters the cytoplasm of the oocyte.

Describe the Epidermis:

The epidermis is avascular (no blood vessels) epithelial tissue.

What is the Epidermis?

The epidermis is composed of the outermost layers of cells in the skin, "epi" in Greek meaning "over" or "upon", which together with the dermis forms the cutis. The epidermis is a stratified squamous epithelium, composed of proliferating basal and differentiated suprabasal keratinocytes which acts as the body's major barrier against an inhospitable environment, by preventing pathogens from entering, making the skin a natural barrier to infection. It also regulates the amount of water released from the body into the atmosphere through transepidermal water loss (TEWL).

What role does the epiglottis play?

The epiglottis is the cartilaginous member that prevents food from entering the trachea during swallowing. - when non-gaseous material enters the larynx(voice box), a coughing reflex is triggered forcing the material back out.

What is the main difference between the wall of the stomach and the wall of the small intestine?

The epithelial layer of the small intestine contains finger-like projections called Villi.

Describe what happens to an erythrocyte as it leaves the marrow and travels into the blood.

The erythrocyte loses its nucleus while still in the marrow. - after entering the blood stream as reticulocytes, they lose the rest of their organelles within 1 to 2 days.

What is respiration?

The exchange of gases between an organism and the external environment. It also refers to the transport of gases within the organism, and the diffusion of gases into and out of the cell.

What are the 4 types of cells found in bone tissue?

The four types of cells are surrounded by an extensive matrix: 1- Osteoprogenitor cells: or osteogenic cells differentiate into osteoblasts. 2- Osteoblasts 3- Osteocytes 5- Osteoclasts

What is the Fovea?

The fovea is a small point on the retina containing mostly cones, the fovea marks the point on the retina where vision is most acute. The fovea is located in the centre of the macula, The fovea is responsible for sharp central vision (also called foveal vision), which is necessary in humans for reading, watching, driving, and any activity where visual detail is of primary importance. In the human eye the term fovea (or fovea centralis) denotes the pit in the retina, which allows for maximum acuity of vision.

What do enzymes do?

The function as a catalyst, lowering the energy of activation for a biological reaction and increasing the rate of that reaction.

What is the function of the loop of Henle?

The function of the loop of Henle is to increase the solute concentration and thus the osmotic pressure of the medulla. - as filtrate descends the loop of Henle and further into the medulla, water passively diffuses out of the loop of Henle and into the medulla. - The descending loop of Henle has low permeability to salt, so filtrate osmolarity goes up as water leaves and salt stays.

What are fungal cell walls made from?

The fungal cell wall called septa is made from chitin. - Chitin is more resistant to microbial attack than cellulose - it is the same substance of which the exoskeleton of arthropods is made

Describe the path of bile from the gall bladder to the small intestine:

The gall bladder releases bile through the cystic duct, which empties into the common bile duct shared with the liver. The common bile duct empties into the pancreatic duct before connecting to the duodenum at the ampulla of Vater.

What do the mitochondrial genes code for?

The genes in the mitochondrial DNA code for mitochondrial RNA that is distinct from the RNA in the rest of the cell. - mitochondria have their own ribosomes with a sediment coefficient of 55-60S in humans. - However, most proteins used by the mitochondria are coded for by nuclear DNA, not mitochondrial DNA.

The _____ refers to the actual genes, while the ____ refers to the physical/physiological expression of the genes.

The genotype refers to the actual genes, while the phenotype refers to the physical/physiological expression of the genes.

How are the genus and species names given when naming an organism?

The genus and species name are given in order: - They are both written in italics, while the genus is capitalized and the species is not.

What happens to glucose during periods of high blood glucose levels?

The glucose is converted to glycogen and stored in liver and muscle cells, in a process called glyconeogenesis.

Where do lysosomes come from?

The golgi

What does the golgi do to the newly formed proteins?

The golgi organizes and concentrates the proteins as they are shuttled by transport vesicles progressively outward from one compartment or cisterna of the golgi to the next. The golgi may change proteins chemically by glycosylation or by removing amino acids. Some polysaccharide formation also takes place within the golgi. The end product of the golgi is a vesicle full of proteins. these proteins filled vesicles may either be expelled from the cell as secretory vesicles, released from the golgi to mature into lysosomes, or transported to other parts of the cell such as the mitochondria or even back to the ER.

Which stage is the growth stage for fungi?

The haploid stage, which also dominates.

What does the cardiovascular system consist of?

The heart, blood and blood vessels.

The heme group contains an ___ ___ held in a heterocyclic ring known as a _____.

The heme group contains an iron ion held in a heterocyclic ring known as a porphyrin. - The iron ion is bonded to 4 nitrogen atoms in the centre of the ring, all lying in the same plane, and with the globular subunit through a histidine residue.

How does the hypothalamus connect to the posterior pituitary gland?

The hypothalamus connects to the posterior pituitary gland via a specialized group of nerve cells called the Neurosecretory cells. - Thus, hormones travel from the hypothalamus to the posterior pituitary via nerve axons.

What controls the release of the anterior pituitary hormones and how?

The hypothalamus controls the release of the anterior pituitary hormones with releasing and inhibitory hormones of its own. - These inhibitory and releasing hormones are carried to the capillary bed of the anterior pituitary by small blood vessels. - The release of the releasing and inhibitory hormones is, in turn, controlled by nervous signals throughout the nervous system.

How does the body heat itself up if cold or freezing?

The hypothalamus, part of the autonomic NS, will initiate shivering upon stimulation by receptors in the skin and spinal cord. SHivering is the rapid contraction of skeletal muscle to warm the body, since contraction of skeletal muscle produces large amounts of heat.

How does the image appear on the retina and why?

The image on the retina is real and inverted because the eye acts as a converging lens and the object is outside the focal distance.

A patient who has lost a large volume of blood will secrete excess aldosterone from the adrenal cortex. What effect will this increased secretion of aldosterone have on the patient's blood concentrations of sodium and potassium?

The increased secretion of aldosterone causes blood concentrations of sodium ions to increase and the blood concentration of potassium ions to decrease.

What is the second line of defence to pathogens?

The inflammatory response

What two layers of cells surrounds the secondary oocyte that is awaiting fertilization in the fallopian tubes?

The inner zona pellucida and the outer corona radiata

What is the integumentary system?

The integumentary system is the organ system that protects the body from damage, comprising the skin and its appendages (including hair, scales, feathers, hoofs, and nails). The integumentary system has a variety of functions; it may serve to waterproof, cushion, and protect the deeper tissues, excrete wastes, and regulate temperature, and is the attachment site for sensory receptors to detect pain, sensation, pressure, and temperature. In most terrestrial vertebrates with significant exposure to sunlight, the integumentary system also provides for vitamin D synthesis. - the skin, hair, nails, glands and some nerve endings make up the integumentary system, - Hair, nails and some nerves are derivatives of embryonic epidermis.

Through which type of junction do action potentials spread from one cardiomyocyte to the next?

The intercalated discs contain gap junctions through which the the AP spreads from one cardiac cell to the next via electrical synapses.

Which chambers of the heart pump oxygenated blood?

The left atrium and left ventricle

What part of the heart contracts with the most force and why?

The left ventricle contracts with the most force because it needs to propel the blood through the entire systemic circulation.

Where does the light go from the lens?

The light travels through the gel-like vitreous humor and onto the retina.

What is the likelihood genes located on the same chromosome will remain together during cross over is prophase I?

The likelihood is indirectly proportional to the distance separating them. The closer the two genes are together, the more likely they will be transferred together. - If genes loci are close together, they are said to be linked and they have a high chance of crossing over together. - If gene loci are far apart from each other on a chromosome, they are said to be unlinked and have a low chance of crossing over together.

What role does the liver have in glucose and glycogen metabolism?

The liver regulates the blood glucose levels, so liver cells are of the few cell types capable of reforming glucose from glycogen and releasing it back into the blood stream.

Which is the only neuron that uses epinephrine/norepinephrine?

The long, post-ganglionic neuron of the sympathetic NS

What is one role the low pH of the stomach plays in regards to ingested bacteria?

The low pH also helps kill ingested bacteria.

Veins and venules are similar to arteries and arterioles except for what main difference?

The lumen of veins and venules is significantly larger. They also have much less smooth muscle wrapped around them.

What surrounds the lungs?

The lungs are surrounded by the visceral pleura and the parietal pleura. - The visceral pleura is directly on the lungs and the parietal pleura is closer to the inside of the body cavity.

What does the luteal surge cause?

The luteal surge causes the follicle to burst, releasing the egg (secondary oocyte) into the body cavity.

Why does the Luteal Surge occur when estradiol typically inhibits further LH secretion from the anterior pituitary?

The luteal surge results from a positive feedback loop of rising estrogen levels which increase LH levels, which thus increases estrogen.

Where does the lymphatic system empty in the body?

The lymph system empties into large veins at the thoracic duct and the right lymphatic duct

How do lymph vessels prevent fluid from back-flowing?

The lymph vessels are constructed with intermittent valves, which allow fluid to flow in only one direction.

What happens to a macrophage once it has engulfed an antigen marked microbe?

The macrophage will present the antigenic determinant of that microbes antigen on its cell surface for B lymphocyte to find - The macrophage is now known as an APC macrophage or Antigen Presenting Cell Macrophage

What is the Macula?

The macula or macula lutea (from Latin macula, "spot" + lutea, "yellow") is an oval-shaped highly pigmented yellow spot near the center of the retina of the human eye. It has a diameter of around 5 mm and is often histologically defined as having two or more layers of ganglion cells. Near its center is the fovea, a small pit that contains the largest concentration of cone cells in the eye and is responsible for central, high resolution vision. The macula also contains the parafovea and perifovea. Because the macula is yellow in colour it absorbs excess blue and ultraviolet light that enter the eye, and acts as a natural sunblock (analogous to sunglasses) for this area of the retina. The yellow colour comes from its content of lutein and zeaxanthin, which are yellow xanthophyll carotenoids, derived from the diet. Zeaxanthin predominates at the macula, while lutein predominates elsewhere in the retina. There is some evidence that these carotenoids protect the pigmented region from some types of macular degeneration. Structures in the macula are specialized for high acuity vision. Within the macula are the fovea and foveola which contain a high density of cones (photoreceptors with high acuity).

For the MCAT, what is the main effect of Aldosterone?

The main effect of aldosterone is the reabsorption of Na⁺ and the secretion of K⁺ in the collecting tubule of the kidney.

What are the main effects of the endocrine system?

The main effects of the endocrine system are to alter metabolic activities, regulate growth and development, and guide reproduction. - the endocrine system works in conjunction with the nervous system... many endocrine glands are stimulated by neurons to secrete their hormones.

Where does the major absorption of fat occur in the body?

The major absorption of fat occurs in the liver and adipose tissue. - chylomicrons stick to the side of capillary walls where lipoprotein lipase hydrolyzes the triglycerides, the products of which immediately diffuse into the fat and liver cells. - these fatty acids that cross into the liver or adipose cells, are recombined with glycerol to form triglycerides at the smooth endoplasmic reticulum, or oxidized for fuel. - thus, the first stop for most of the digested fat is the liver.

Describe the structure of a flagellum or cilium:

The major component of a flagellum or cilium is the axoneme. The axoneme contains 9 pairs of microtubules forming a circle around 2 lone microtubules in an arrangement known as 9+2. - The cross bridges connecting each of the outer pairs of microtubules are made from the protein dynein. These cross bridges cause the microtubule pairs to slide along side their neighbors creating a whip action in cilia and causing fluid to move laterally, or a wiggle action in flagella causing fluid to move away from the cell.

What are the major functions of the large intestine?

The major functions of the large intestine are water absorption and electrolyte absorption.

What do the Mesodermal cells develop into?

The mesodermal cells develop into the stuff that lies between the inner and outer coverings of the body, the bone, the muscle and the rest. - musculoskeletal, circulatory, excretory, connective and digestive systems.

What are the ends of a typical long bone composed of?

The metaphysis and epiphysis.

What happens to the micelles after they deliver their cargo or monoglycerides and fatty acids to the enterocytes?

The micelles shuttle back to the chyme to pick up more fat digestates.

What is the main purpose of the microvilli?

The microvilli act to increase the surface area of the intestinal wall even further.

What are the mitochondria of cardiac muscle like compared to those of skeletal muscle?

The mitochondria of cardiac muscle are larger and far more numerous.

Do all muscles fibres of a single muscle all contract at once?

The muscle fibres of a single muscle do not all contract at once. Instead, from 2 to 2000 fibres spread throughout the muscle are innervated by a single neuron. - the neuron and the muscle fibres that it innervates are called a motor unit. - motor units are independent of each other.

What is the net effect of Insulin?

The net effect of insulin is to lower blood glucose levels, by stimulating the uptake of glucose by muscle and adipose cells.

What is the Net Effect of the Distal Tubule?

The net effect of the distal tubule is to lower filtrate osmolarity by removing sodium and potassium. Thus, filtrate becomes more diluted.

What is the net result of the production of HCl in the parietal cells?

The net result is to lower the pH of the lumen of the stomach and increase the pH of the blood.

What is the net result of the proximal tubule?

The net result of the secretion and reabsorption in the proximal tubule is a decreased volume of filtrate in the nephron while changing the solute composition without changing osmolarity. - Na⁺ is actively pumped out of the proximal tubule - Cl⁻ and H₂0 follow passively down their concentration gradients - Glucose and amino acids are also reabsorbed here

Which cells of the body are unaffected by insulin?

The neurons of the brain.

What are the 2 direct peptide hormones synthesized by the hypothalamus and where are they stored?

The neurosecretory cells of the hypothalamus synthesize the 2 direct peptide hormones: Vasopressin (ADH) and Oxytocin. - Both ADH and oxytocin are synthesized by the hypothalamus and travel down the nerve axons to the posterior pituitary where they are stored.

What happens to the notochord after neurulation?

The notochord eventually degenerates, while the neural tube forms from the neural plate to become the spinal cord and brain, and most of the nervous system.

Where is the nucleolus located and what occurs inside it?

The nucleolus is located inside the nucleus. This is where rRNA is transcribed and the subunits of the ribosome are assembled. There is no membrane separating the nucleolus from the nucleus.

What wraps the nucleus?

The nucleus is wrapped in a double phospholipid bilayer called the Nuclear envelope or nuclear membrane. It is perforated with large holes called nuclear pores to allow RNA to leave the nucleus, though DNA cannot leave.

Primary structure:

The number and sequence of amino acids in a polypeptide

What is the pH of the fluid in the duodenum and why?

The pH of the fluid in the duodenum is 6 due mainly to bicarbonate ion secreted by the pancreas.

What is the pH of the small intestine and why?

The pH of the small intestine is around 7.6 because of the exocrine glands that secrete a fluid with this pH.

What role does the parasympathetic vagus nerve play in heart contractions?

The pace of the SA Node is faster than normal heartbeats but the vagus nerve innervates the SA Node, slowing the contractions.

The parasympathetic ANS deals with ____ and ____ responses, and would have what effects on the body?

The parasympathetic ANS deals with rest and digest responses: - slows heart rate and increases digestive and excretory activity

What hormones does the parathyroid gland secrete and where is the parathyroid gland located?

The parathyroid gland secretes parathyroid hormone; PTH. - There are 4 parathyroid glands attached to the rear or dorsal surface of the thyroid gland. - the parathyroid is an endocrine gland.

What are the 2 important endocrine hormones released by the pancreas?

The peptide hormones insulin and glucagon, and since they are endocrine, they are released directly into the blood.

Though arteries, for the most part, carry oxygenated blood to the body, which artery carries the most deoxygenated blood in the body and why?

The pulmonary artery contains the most deoxygenated blood in the body because it carries all deoxygenated blood from the heart to the lungs in order for it to be reoxygenated.

What is the major contributor for blood pressure in the blood vessels/veins?

The pumping force of the heart

The epithelial cells of the Proximal Convoluted Tubule contain a brush border similar to that of the small intestine, what is its main purpose?

The purpose of this brush border is to increase the surface area available to reabsorb solutes from the filtrate. - since the brush border is made from villi and NOT cilia, it has little to no effect on the direction or rate of movement.

What is the name of the sphincter that allows the passage of food from the stomach to the duodenum of the small intestine?

The pyloric sphincter - the semifluid chyme is squeezed through the pyloric sphincter into the duodenum.

Mass:

The quantitative measure of an object's inertia. An object's mass tells us how much that object will resist a change in its motion. Measured in kg.

How is the rate of breathing affected and to what does it respond?

The rate of breathing is affected by central chemoreceptors in the medulla, and peripheral chemoreceptors located in the carotid arteries and aorta. - Both types monitor CO₂ concentration in the blood and increase breathing rate when levels are too high. - Oxygen concentration and pH are mainly monitored by peripheral chemoreceptors.

What would happen in the presence of a carbonic anhydrase inhibitor?

The rate of gas exchange in the lungs would decrease because carbonic anhydrase is a catalyst that would normally increase the rate of the reactions. Since it is inhibited, the rate of its reaction is decreased.

What does the ratio of the muscle fibre type within any given muscle depend on?

The ratio depends upon the contraction requirements of the muscle and upon the genetics of the individual.

What is the reason as to why milk is not normally produced before birth?

The reason milk is not normally produced before birth is due to the inhibitory effects of milk production by progesterone and estrogen. - Although the hypothalamus has a stimulatory effect on the release of all other anterior pituitary hormones, it mainly inhibits the release of prolactin.

A cell membrane is normally slightly passively permeable to potassium ions. What would happen to the neuron's resting potential if the membrane became impermeable to potassium ions?

The resting potential would become more positive because potassium ion concentration would increase inside the cell.

Through which duct does the lymph from the right arm and head enter the blood?

The right lymphatic duct... the rest of the body is drained by the thoracic duct

What does the sarcolemma do?

The sarcolemma is a modified membrane that wraps several myofibrils together to form a muscle cell or muscle fibre. - many muscle fibres are bound into a fasciculus and many fasciculae make up a single muscle.

Explain how a satellite orbits Earth:

The satellite in orbit around the Earth is constantly falling towards Earth due to gravity. Since there must be a force creating the Fc, gravity creates the Fc that makes the satellite orbit the Earth rather than fly off in a direction of its velocity. A satellite is constantly falling toward Earth's centre but its velocity makes it continually miss the ground, and always by the same distance.

What sort or receptor system is preferred for prolonged change to occur, such as that involved in memory?

The second messenger system is preferred, where a G-protein is attached to the receptor protein along the inside of the post-synaptic membrane. - When the receptor is stimulated by the NT, part of the G-protein, called the alpha-subunit, breaks free.

Comparing the primary and secondary immune responses, which is faster and more potent?

The secondary is faster and more potent. - it only takes 5 days to reach its full potential

At what stage of meiosis II is the secondary oocyte arrested at?

The secondary oocyte is arrested at metaphase II of meiosis II, in the ovary within the follicle.

What happens to the secondary oocyte once it is released into the body cavity?

The secondary oocyte is swept into the Fallopian tubes or oviduct by the fimbriae of the fallopian tubes.

Enzyme specificity:

The selectivity of an enzyme; enzyme can only bond to certain substrates. Normally, enzymes are designed to work on a single substrate or group of closely related substrates.

Where does the sensory portion of the Autonomic NS receive signals from?

The sensory portion of the ANS receives signals from the viscera (the organs inside the body cavity). - then the motor portion of the ANS conducts these signals to the smooth muscle, cardiac muscle, and glands.

What is glycolysis?

The series of reactions that breaks a 6-carbon glucose molecule into two 3-carbon molecules of pyruvate. Glycolysis is glucose metabolism.

What do the Sertoli cells of the testes do?

The sertoli cells are stimulated by FSH to surround and nurture the spermatocyte and spermatids.

What is cellular respiration?

The set of metabolic reactions that take place at the cellular level to convert energy from nutrients into ATP.

Induced Fit Model:

The shape of both the substrate and enzyme are altered upon binding. The conformational change increases specificity and helps the reaction proceed. In a reaction with more than one substrate, the enzyme may orient the substrates relative to each other, creating optimal conditions for a reaction to take place.

Center of Mass:

The single point at which, for the purposes of a simple mechanics problem, all the mass of that system can be considered to be concentrated. The point through which a single force may be applied in any direction causing all points on the system to accelerate equally.

How do the 3 small bones of the middle ear work in hearing?

The small bones act as a lever system translating the wave to the oval window of the inner ear. These bones change the combination of force and displacement from the inforce to the outforce. The displacement is actually lessened which creates an increase in force. In addition, the oval window is smaller than the tympanic membrane, acting to increase pressure. This increase in force is necessary because the wave is being transferred from the air in the outer ear to a more resistant fluid (the perilymph) within the inner ear.

Which organelle within the enterocyte converts monoglycerides and fatty acids back to triglycerides?

The smooth er: - once this occurs, these newly synthesized triglycerides aggregate inside the ser lumen with some cholesterol and some phospholipids. - these amphipathic molecules orient themselves like a micelle with their charged ends pointing outward toward the aqueous solution of the lumen. - apoproteins attach themselves to the outside of these globules. - these globules then move to the golgi apparatus where they are released into from the cell into the interstitial fluid via exocytosis. These globules are now called cholymicrons, and they move to the lacteal and enter the lymphatic system.

Why is a person short of breath during an asthma attack?

The smooth muscle surrounding the bronchioles spasms and constricts, causing the shortness of breath.

How does the Na⁺/K⁺ work?

The sodium/potassium pump moves 3 Na⁺ ions out of the cell and brings 2 K⁺ ions into the cell, to create the resting potential. - The purpose of the Na⁺/K⁺ pump is to increase the positive charge along the membrane just outside the cell relative to the charge along the membrane just inside the cell. In other words, the outside of the cell becomes more electro positive compared to the inside of the cell. - as the electrochemical gradient of Na⁺ increases, the force pushing the Na⁺ back into the cell also increases. The rate at which Na⁺ passively diffuses back into the cell increases until it equals the rate at which it is being pumped out of the cell. The same thing happens for potassium. - When all rates reach equilibrium, the inside of the membrane has a negative potential difference (voltage) compared to the outside. This potential difference is called the resting potential.

How old is our solar system and earth?

The solar system is about 4.6 byo, and Earth is about 4.5 byo. - Though due to the volatile nature of Earth, no rocks exist older than 3.9byo.

Water

The solvent in which the chemical reactions of living cells take place. 70 to 80 % of a cell's mass is water. A polar molecule that can hydrogen bond

Where do the spermatozoa become activated for fertilization?

The spermatozoa undergo a process called Capacitation in the vagina, where they are activated for fertilization. - Capacitation involves the destabilisation of the acrosomal sperm head membrane allowing greater binding between sperm and oocyte. This change is facilitated by the removal of steroids (e.g. cholesterol) and non-covalently bound epididymal/seminal glycoproteins. The result is a more fluid membrane with an increased permeability to Ca2+.

The stomach is the first place of ______ digestion, and ___ absorption takes place in the stomach!

The stomach is the first place of protein digestion, and NO absorption takes place in the stomach!

A major problem with digestion is that food may move too quickly through the digestive tract and not be digested properly, what is the solution for this?

The stomach is the solution, where it holds large amounts of food and releases small amounts into the duodenum to be digested. - This process is regulated by the hormones cholecystokinin, which is released from the small intestine to decrease motility of the stomach allowing the duodenum more time to digest fat.

Catabolism:

The sum total of all processes in an organism which break down chemicals to produce energy and simple chemical building blocks.

What forms the synovial capsule?

The synovial fluid is held within the synovial or articular capsule. The capsule is formed by the articular cartilage that lines the ends of both bones in the synovial joint.

Where are the target receptors for T3 and T4?

The target receptors for T3 and T4 are in the nucleus of the cell.

Inertia:

The tendency of a body to maintain is state of rest or uniform motion unless acted upon by an external force

What does the Theory of the Survival of the Fittest predict regarding a specie's niche?

The theory of the survival of the fittest predicts that one species will exploit the environment more efficiently, eventually leading to the extinction of the other with the same niche.

What is the thick filament of a sarcomere made of?

The thick filament of the sarcomere is made of the protein myosin. - several long myosin molecules wrap around each other to form one thick filament. Globular heads protrude along both ends of the thick filament. - Myosins comprise a family of ATP-dependent motor proteins and are best known for their role in muscle contraction and their involvement in a wide range of other eukaryotic motility processes. They are responsible for actin-based motility. The term was originally used to describe a group of similar ATPases found in striated and smooth muscle cells.

What is the thin filament of a sarcomere made of?

The thin filament of a sarcomere is composed of a polymer of the globular protein actin.

Tertiary Structure:

The three dimensional shape formed when the peptide chain curls and folds.

Why is the thyroid gland an exception to the fact that hormone glands produce only one type of hormone, not two?

The thyroid gland is an exception because it secretes both T3 and T4, which are tyrosine derivatives, and it also produces calcitonin which is a peptide hormone.

What are the Thyroid hormones and where is the thyroid gland located?

The thyroid hormones are T3 (triiodothyronine), T4 (thyroxine) and calcitonin. T3 and T4 are tyrosine derivative hormones and calcitonin is a peptide hormone. - The thyroid gland is located along the trachea, anterior to the larynx, on the ventral side of the trachea. - the thyroid gland is bi-lobed, with one of its two lobes on either side of the trachea.

What effect do the Thyroid hormones have in the body?

The thyroid hormones increase the transcription of large numbers of genes in nearly all cell of the body.

How do the cells in the retina work?

The tips of these cells contain light sensitive photochemicals called pigments that go through a chemical change when one of their electrons is struck by a single photon.

What is the trachea composed of?

The trachea is composed of ringed cartilage covered by ciliated mucous cells. - the mucous and cilia collect dust and usher it towards the pharynx.

Where is the trachea located?

The trachea is the windpipe and it is located in front of the esophagus

What is the slowest part of the process of nervous system cellular communication?

The transmission of the signal from one cell to another across the synapse.

What is the treatment in the case where a mother's Rh+ antibodies are attacking the Rh+ blood of the fetus?

The treatment is complete replacement of the fetal blood with Rh-negative blood for the first few weeks of life. It can also be prevented if the Rh- mother is injected with anti-Rh antibodies after delivering the first Rh+ baby

Where are the tropic peptide hormones synthesized and what is their function?

The tropic peptide hormones are synthesized in the hypothalamus. The tropic peptide hormones either release or inhibit the release or anterior pituitary hormones.

How do the tropic peptide hormones reach the anterior pituitary?

The tropic peptide hormones synthesized in the secretory cells of the hypothalamus reach the anterior pituitary via the hypothalamic-hypophyseal portal system.

Describe the early moments of the big bang

The universe began as a tiny spec of highly concentrate mass and exploded outward. In the early moments, only hydrogen gas existed. As the universe cooled, helium was able to form. The explosion was irregular, and gravitational forces created clumping of the mass. Heavier elements, and solar systems formed from the clumps of mass.

What is the purpose of the villi in the small intestine?

The villi increase surface area of the intestinal wall allowing greater digestion and absorption.

What is the larynx?

The voice box, contains the vocal chords. - The larynx sits behind the epiglottis

What would happen to the volume of urine produced in an infant with narrowed renal arteries?

The volume of urine would decrease because there would be decreased blood flow to the glomeruli, which in turn would glomerular filtration rate and thus filtrate amount.

What are the 4 paths that the alpha-subunit of the G-protein may take upon NT activation of the post-synaptic receptor?

The α-subunit may: 1) activate separate specific ion channels 2) activate a second messenger (cAMP or cGMP) 3) activate intracellular enzymes 4) activate gene transcription

What is the general effect of the T3 and T4 hormones on the body?

Their general effect is to increase the basal metabolic rate (the resting metabolic rate).

What is the result of the thyroid hormone's high affinity for their binding proteins in the plasma and in the nucleus?

Their high affinity to their binding proteins in the plasma and in the nucleus create a latent period in their response and increases the duration of the effect of the thyroid hormones.

How does the notochord differ from chordates in members of the subphylum Vertebrata?

Their notochord is replaced by a segmented cartilage or bone structure. - They also have a distinct brain enclosed in a skull. - Most chordates are vertebrates

What is the function of glycolipids?

Their role is to provide energy and also serve as markers for cellular recognition

What does it mean if your net force is greater than µsFn?

Then the object is sliding along the surface. If this is the case, ignore the static friction, which is now irrelevant because the object is moving, and subtract the magnitude of the kinetic frictional force from the net force to arrive at a new net force that include friction.

What does it mean if your calculated net force is less than µsFn?

Then your system is probably not sliding on the surface because static friction will hold it in place, given: fs≤µsFn, not moving If there is no acceleration, the static friction is equal to and opposite the calculated net force.

How many adrenal glands are there and what type of hormone do each produce?

There are 2 adrenal glands: 1- Adrenal Cortex: steroids 2- Adrenal Medulla: catecholamines (NE and E)

How many muscle layers exist in the wall of the stomach and what is this called?

There are 3 muscles layers in the wall of the stomach, collectively called the Muscularis.

How many types of cones are there?

There are 3 types of cones, each with a different pigment that is stimulated by a slightly different spectrum of wavelengths.

How many layers or strata are there in the epidermis and what are they?

There are 5 layers of the epidermis: - the deepest layer contains the Merkel cells and stem cells. - the stem cells continually divide to produce keratinocytes and other cells. - Keratinocytes are pushed to the top layer - as they rise, they accumulate keratin and die, losing their cytoplasm, nucleus, and other organelles. - the outermost layer of epidermis consists of 25-30 layers of flat, dead cells.

How can you out compete noncompetitive inhibition?

There is no way to overcome noncompetitive inhibition, and increasing substrate concentration will not overcome the inhibitor. - the inhibitors do NOT lower enzyme affinity for substrate, though they alter conformation of the active site so that the enzyme cannot bind as tightly to substrate,

If the velocity of an orbiting satellite around Earth, is doubled, what effect would it have on the gravitational force it experiences?

There would be no effect on the gravitational force because velocity is not involved. The only factors involved are mass and radius. F=Gm₁m₂/r²

Why do they call cAMP, cGMP and calmodulin second messengers and how do they work?

These are second messengers because the hormone that binds the membrane-bound receptor is the original, or first messenger, to the cell. - This second messenger activates or deactivates enzymes and/or ion channels and often creates a cascade if chemical reactions that amplifies the effect of the hormone. - A cascade is one way that a small concentration of hormone can have a significant effect.

What have experiments that attempt to recreate the atmosphere of early earth succeeded at doing?

These experiments have resulted in the autosynthesis of molecules such as urea, amino acids, and even adenine. - One of the early experiments to make such an attempt was the Urey-Miller Experiment.

What results when the main functions of the large intestine fail?

When the large intestine fails to absorb water or electrolytes, diarrhea results.

What is the Buffy coat made from?

White blood(leukocytes) cells and platelets

How is the Oxygen dissociation curve affected with an increase in carbon dioxide pressure?

With an increase in CO₂ pressure, the oxygen dissociation curve is shifted to the right. - this indicates a lowering of Hemoglobin's affinity for oxygen. - thus, with increased CO₂, the Hb can not bind O₂ as well.

How is the Oxygen dissociation curve affected with an increase in hydrogen ion concentration?

With an increase in hydrogen ion concentration comes a lowered pH, thus the curve is shifted to the right, thus indicating a lowered affinity for O₂. - This is called the Bohr effect, wherein H⁺ ions bind to Hb, releasing O₂ bound by Hb to the peripheral tissue.

Describe the structure of each the Villi:

Within each Villus are a capillary network and a lymph vessel, called a lacteal. - Nutrients absorbed through the wall of the small intestine pass into the capillary network and the lacteal. - On the apical (lumen side) surface of the cells of each villus are much smaller finger-like projections called Microvilli.

Where does the actual gas exchange occur in the lungs?

Within the alveoli

How does the thymus test T lymphocytes?

Within the thymus, T lymphocytes are tested against self-antigen, or antigen that are found on normal body tissue. If the T lymphocyte binds to a self-antigen, the T lymphocyte will be destroyed to prevent autoimmune diseases If the T lymphocyte does not bind to self-antigens, it is released into the blood and lymphoid tissue after differentiating into Helper, Memory, Suppressor and Killer T cells

What does yellow bone marrow contain?

Yellow bone marrow contains adipose cells for fat storage.

Is bone a living tissue?

Yes, bone is a living tissue.

Is cardiac muscle striated like skeletal muscle?

Yes, cardiac muscle is striated like skeletal muscle, which means that cardiac muscle is also composed of sarcomeres.

What are inclusion bodies and do Prokaryotes possess them?

Yes, prokaryotes have inclusion bodies, which are granules of inorganic or organic matter. They may or may not be bound by a single layer membrane

What types of molecules to prokaryotic Plasma membranes contain?

along with phospholipids, there are glycolipids, hopanoids... but unlike eukaryotic membranes, proks do not contain steroids such as cholesterol. Proks also have proteins embedded in the PM.

Animals can only eat ___ linkages, whereas bacteria can break down ___ linkages.

alpha; beta

The liver is also responsible for the processing of nitrogenous waste which is produced by the absorption and metabolism of excess ____ ______, also called _____.

amino acids also called deamination

What is an antigenic determinant that is removed from the antigen called?

an antigenic determinant that is removed from the antigen is called a Hapten

Glycolysis is the first stage of ______ and ______ respiration.

anaerobic and aerobic; glycolysis will operate in both the presence and absence of oxygen, it neither requires oxygen, nor is poisoned by it. The ten step process of glycolysis is entirely anaerobic.

Describe how Temp affects enzymatic reactions:

at first, as temp increases, the rate of the reaction also increases, but at some point the enzyme denatures and the rate of the reaction drops off precipitously. Optimal temp for enzymes in the human body is 37°C

How fast do object on an incline between 0-90° accelerate?

at some fraction of g

Why are the endocrine hormones referred to as general hormones?

b/c they are released into the body fluids, often the blood, and may affect many cell types in a tissue, and multiple tissues in the body.

Why does a block of wood slide slower down an inclined plane than does a block of ice?

because the kinetic frictional force is greater on the wooden block.

What is the optimal pH for pepsin in the stomach?

below 2

What is the optimal pH for trypsin in the small intestine?

between 6 and 7

Phospholipids are amphipathic, thus they contain?

both a hydrophobic and hydrophilic region, or a nonpolar and polar region, respectively.

Most molecules of living cells are broken apart via _______ and formed via _______ synthesis.

broken down byHydrolysis; formed by dehydration synthesis

What creates the plateau after depolarization of the cardiac muscle?

by the effects of slow voltage-gated calcium channels, allowing calcium to enter and hold the inside of the membrane at a positive potential difference

What is the net result of fluid exchange by the capillaries?

a 10% loss of fluid to the interstitium, thus to the lymphatic system

What are the 3 components that make up nucleotides?

a five carbon sugar, a nitrogenous base, a phosphate group

Tension:

a force acting through a flexible object with no mass, such as a string or rope. Tension is equal throughout the rope as long as there is no friction acting on the rope. At any point in a rope there is a tension force pulling in equal and opposite directions. We only use the force pulling away from our system. Tension requires an equal force at both ends of the rope, and the tension in the rope is equal to only one of the forces, not both. This is because, since a rope has no mass, if a net force was applied to only on end, the rope would accelerate in the direction of the force at an infinite rate.

Define Systole:

a force that drives blood out of the heart. Without qualifiers, it usually means the contraction of the left ventricle. When the smaller, upper atria chambers contract in the first phase of systole, they send blood down to the larger, lower ventricle chambers. When the lower chambers are filled and the valves to the atria are closed, the ventricles contract in the second phase, sending blood from the left ventricle to the aorta and body, and from the right ventricle to the lungs. Thus, the atria and ventricles contract in sequence (the atria feeding blood into the ventricles), while the left and right ventricles contract at the same time. - occurs when the ventricles contract and force blood out if the heart. - Highest blood pressure due to blood pumping out of ventricles

Kinases:

a kinase is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP, to specific substrates, a process referred to as phosphorylation. Kinases are part of the larger family of phosphotransferases. Kinases are not to be confused with phosphorylases, which carry out phosphorolysis, the breaking of a bond using an inorganic phosphate group; or with phosphatases, which remove phosphate groups.

During the female menstrual cycle increasing the levels of estrogen cause:

a positive feedback response, stimulating LH secretion from the anterior pituitary, leading to the luteal surge.

What is the acceleration of an object down an inclined plane?

a=gsinθ

Centripetal Acceleration:

a=v²/r - is always pointing to the centre of the circle, the object is always accelerating towards the centre of the circle. The direction of acceleration is always changing but the magnitude of acceleration is constant.

What is the formula for average acceleration?

a=∆v/∆t

Cholinergic receptors are receptors for?

acetylcholine

The sole NT used by the somatic nervous system is?

acetylcholine on the effector organ.

Kinases often phosphorylate other enzymes in order to?

activate them

Lymph flow in an _____ individual is considerably greater than in an individual at ____.

active; rest

What are the 4 nitrogenous bases in nucleotides?

adenine, guanine, cytosine, thymine, Uracil is in RNA instead of thymine

Capillaries are found close to ____?

all cells of the body

How is smooth muscle shaped?

cell is tapered

What does it mean when a synapse is cholinergic?

cholinergic typically refers to acetylcholine in the neurological sense. The parasympathetic nervous system, which uses acetylcholine almost exclusively to send its messages, is said to be almost entirely cholinergic. Neuromuscular junctions, preganglionic neurons of the sympathetic nervous system, the basal forebrain, and brain stem complexes are also cholinergic. In addition, the receptor for the merocrine sweat glands are also cholinergic, since acetylcholine is released from post-ganglionic sympathetic neurons. In neuroscience and related fields, the term cholinergic is used in the following related contexts: A substance (or ligand) is cholinergic if it is capable of producing, altering, or releasing acetylcholine ("indirect-acting") or mimicking its behaviour at one or more of the body's acetylcholine receptor types ("direct-acting"). A receptor is cholinergic if it uses acetylcholine as its neurotransmitter. A synapse is cholinergic if it uses acetylcholine as its neurotransmitter.

Vitamins are classified as?

coenzymes

Distal tubule empties into ____ ____

collecting duct

___ ___ concentrates the urine

collecting duct

Cones distinguish _____

cones distinguish colors

Polarity

polarity refers to a separation of electric charge leading to a molecule or its chemical groups having an electric dipole or multipole moment. Polar molecules interact through dipole-dipole intermolecular forces and hydrogen bonds. Molecular polarity is dependent on the difference in electronegativity between atoms in a compound and the asymmetry of the compound's structure. For example, a molecule of water is polar because of the unequal sharing of its electrons between oxygen and hydrogen in which the former has larger electronegativity than the latter, resulting in a "bent" structure, whereas methane is considered nonpolar because the carbon shares the electrons with the hydrogen atoms almost uniformly. Polarity underlies a number of physical properties including surface tension, solubility, and melting- and boiling-points.

GTP-bound tubulin favors ?

polymerization at the + end

Saturated fatty acids:

possess only single carbon-carbon bonds, with no double bonds. Saturated fatty acids are long-chain carboxylic acids that usually have between 12 and 24 carbon atoms and have no double bonds. Thus, saturated fatty acids are saturated with hydrogen (since double bonds reduce the number of hydrogens on each carbon). Because saturated fatty acids have only single bonds, each carbon atom within the chain has 2 hydrogen atoms (except for the omega carbon at the end that has 3 hydrogens).

All proteins have a _____ structure and most have a ____ structure.

primary; secondary.

Glycoproteins:

proteins with carbohydrate groups attached. - components of cellular plasma membranes.

Reabsorption and secretion mostly in the ____ ____

proximal tubule

What is the Binomial Theorem and what does it predict?

p²+2pq+q²=1 p+q=1 - this theorem predicts the genotype frequency of a gene with only two alleles in a population in Hardy-Weinberg equilibrium. - a dominant allele is labelled 'p', the recessive allele is labelled 'q'. - p= homozygous dominant - q= homozygous recessive - 2pq= heterozygous

If 36% of a population is homozygous dominant, what percentage of the population are heterozygotes?

p²+2pq+q²=1 p+q=1 - p²=0.36, p=0.6 - q=0.4 therefore, 2pq=2x0.6x0.4= 0.48

How do you determine if two dominant alleles will come together during fertilization if 80% of the alleles in a population are dominant?

p²=0.8²=0.64 Therefore, the genotype frequencies for this population are AA 64%, Aa 32% and aa 4%.

___-selected species put their energy into reproduction over parental care. This works in unstable or unpredictable environments.

r-selected - the ability to reproduce quickly is crucial - high reproduction rate (fecundity) - small body size - early maturity onset - short generation time - ability to disperse offspring widely

An individual with type O blood has 2 ____ alleles.

recessive

What are the major functions of Steroids?

regulate metabolic activities

Filtration occurs in the ___ ____

renal corpuscle

Coefficients of Friction:

represent the fractions of the normal force that will equal the static and kinetic frictional forces.

What type of structure contributes to the conformation of the protein?

secondary structure

With fungi, meiosis is part of ______ reproduction.

sexual

Paracrine:

short distance signalling; signal generated by one cell and interacts with receptors on neighbouring cells, transported by diffusion through interstitial fluid, acts on cells near the original secreting cell

Sympathetic pre-ganglionic neurons are ____ while post-ganglionic neurons are ____.

short; long

Is cardiac muscle nucleated?

single nucleus

Is smooth muscle nucleated?

single nucleus

How many nuclei do smooth muscle cells contain?

smooth muscle cells contain one nucleus

Water molecules surround or ________ a hydrophilic molecule separating it from the group.

solvate

______ is a carbohydrate polymer, stored in plants and digested by animals.

starch

The structure and motility of the cell is determined by a network of filaments known as the ___?

cytoskeleton; - the cytoskeleton anchors some cellular components and membrane proteins, moves components within the cell, and moves the cell itself.

A phosphatase _____ something

de-phosphorylates

as chyme is passed from the stomach to the small intestine, the catalytic activity of pepsin:

decreases because of the change in pH from 2 to between 6 and 7. Pepsin's optimal pH is 2.

Muscles cause movement at joints by:

decreasing in length or contracting, thereby bringing the muscle's origin and insertion closer together.

Newton's Law of Universal Gravitation:

states that every mass in the universe exerts an attractive force on every other mass in the universe, and that the force is proportional to both of the masses m₁ and m₂ and inversely proportional to the square of the distance between their centres of mass. F=Gm₁m₂/r²

If a block on an inclined plane does not slide down, what causes it?

static friction

What are the 2 irreversible steps in glycolysis?

steps 1=hexokinase step 3= PFK-1

A given gland produces on of either ____, ____, or ____ ____, but not two.

steroids, peptides, or tyrosine derivatives.

Why does the lens not have a spherical shape?

stiff suspensory ligaments tug on it and tend to flatten it. - these ligaments are connected to the ciliary muscle, which circles the lens.

What are the major functions of triacylglycerols?

store metabolic energy, provide insulation and padding

The AV node:

delays the contraction of the ventricles of the heart

Since proteins and enzymes both contain nitrogen, they are both susceptible to?

denaturation

GDP-bound tubulin favors?

depolymerization

A ______ peptide hormone released from the hypothalamus affects and organ or organ system.

direct

The kingdom of fungi is divided into ?

divisions

When do the hyphae lengthen?

during mitosis

_____ walks along the microtubules towards the - end?

dynein

What are the major functions of Fatty Acids?

eicosanoids can serve as autocrine or paracrine hormones

Cells in the same tissue usually have similar ____; they arise from the same embryonic germ layer.

embryology;

What is called when cells take up substances from the extracellular environment?

endocytosis

Most viruses that infect animals do so by:

entering the host cell via an endocytotic process, meaning, the entire virus (capsid and everything) must enter the cell.

In all cells except the _____ and the cells of the ___ ____, glucose is transported from high concentration to low concentration via facilitated diffusion

enterocytes and cells of the renal tubule.

What separates epithelial tissue from connective tissue?

epithelial tissue lies on top of connective tissue, from which it is usually separated by a basement membrane/ basal surface.

In aerobic respiration, what does the energy from the oxidation of NADH do?

establishes the proton gradient between the matrix and intermembrane space.

Since the SA node is innervated by the vagus nerve, the frequency of self-excitation of the cardiac cells of the SA node is likely to be:

faster than a normal heartbeat because excitation by the vagus nerve decreases the heart rate. - The vagus nerve is a parasympathetic nerve. Heart rate is set by the SA node, and the SA node is innervated by the parasympathetic vagus nerve. - the parasympathetic nerve tonically slows the contractions of the heart to its resting pace.

What is the formula for kinetic friction?

fk=µkFn

What do the female gonads (ovaries) consist of?

follicles and developing oocytes.

The parallel force requires ______.

friction

In which direction are nucleotides or DNA written?

from the 5' → 3' direction. DNA is written so the top strand runs 5'→3' and the bottom strand runs 3'→5'.

What is the formula for static friction?

fs=µsFn

G Cells secrete:

gastrin into bloodstream which stimulates parietal cells to secrete HCl.

What is the relative refractory period?

gives the time during which only an abnormally large stimulus will create an action potential.

In the human brain, ___ cells outnumber neurons 10 to 1.

glial cells

What type of proteins are enzymes?

globular proteins

What happens if the cell already has sufficient ATP?

glucose will be polymerized to the polysaccharide glycogen or converted to fat.

What happens to glucose, galactose and fructose when leaving the enterocyte?

glucose, galactose and fructose are all exported to the basolateral side by facilitated diffusion of the GLUT2 protein and enter the portal vein to the liver.

If the integral or peripheral proteins contain carbohydrates, what are they called?

glycoproteins, and the carbohydrate portion always protrudes toward the outside of the cell

The ____ modifies and packages proteins for use in other parts of the cell and outside the cell.

golgi

If there is no friction and nothing attached to a block on an inclined plane, what are the forces acting on the block?

gravity pushing straight down and the inclined plane pushing back up, thus Fg and Fn.

Taste is called:

gustation

All hormones of the Anterior pituitary have specific target tissues except for which hormone?

hGH

How is the effect of increased protein synthesis by hGH accomplished?

hGH accomplishes increased protein synthesis by increasing amino acid transport across the cell membrane, increasing translation and transcription, and decreasing the breakdown of protein and amino acids.

How does hGH stimulate growth?

hGH stimulates growth by: - increasing occurrences of mitosis - increasing cell size - increasing rate of protein synthesis - mobilizing fat stores - increasing use of fatty acids for energy - decreasing use of glucose

Autonomic pathways are controlled mainly by the ______.

hypothalamus

In which direction does diffusion work for molecules without an electric charge?

in the direction of lower concentration

Where does the centre of mass reside in a uniformly dense system?

in the geometric centre

What other process is reverse transcriptase used for?

in the lab, it is used to reverse transcribe mRNA into complementary DNA called cDNA

Where does transcription take place in eukaryotes?

in the nucleus

Where is the SA Node located?

in the top of the right Atrium

Upon secondary exposure to a pathogen, what type of cell elicits the immune response?

the Memory B-cell

Why are amino acids called alpha amino acids?

the amine is attached to the carbon in the alpha position to the carbonyl.

Hydrogen Bond

the attractive interaction of a hydrogen atom with an electronegative atom, such as nitrogen, oxygen or fluorine, that comes from another molecule or chemical group. The hydrogen must be covalently bonded to another electronegative atom to create the bond. These bonds can occur between molecules (intermolecularly), or within different parts of a single molecule (intramolecularly).[2] The hydrogen bond (5 to 30 kJ/mole) is stronger than a van der Waals interaction, but weaker than covalent or ionic bonds. This type of bond occurs in both inorganic molecules such as water and organic molecules like DNA. Intermolecular hydrogen bonding is responsible for the high boiling point of water (100 °C) compared to the other group 16 hydrides that have no hydrogen bonds. Intramolecular hydrogen bonding is partly responsible for the secondary, tertiary, and quaternary structures of proteins and nucleic acids. It also plays an important role in the structure of polymers, both synthetic and natural.

Estradiol ______ LH secretion from the anterior pituitary.

inhibits

The centre of mass does not have to be located _________ the object.

inside

Where does the krebs cycle take place?

inside the mitochondria

Neurons do not depend upon _____ to obtain glucose.

insulin

Is cardiac muscle involuntary or voluntary?

involuntary

Is the phosphorylation of glucose reversible or irreversible?

irreversible; and it assists in the facilitated diffusion mechanism that transports glucose into the cell, because the phosphorylated molecules of glucose cannot diffuse back through the membrane of the cell, so they are essentially stuck in the cell to continue down the glycolytic cycle.

Oxidative Phosphorylation:

is a metabolic pathway that uses energy released by the oxidation of nutrients to produce adenosine triphosphate (ATP)

Define Lymphocytes:

is a type of white blood cell in the vertebrate immune system. - The three major types of lymphocyte are T cells, B cells and natural killer (NK) cells.

Anabolism:

is the set of metabolic pathways that construct molecules from smaller units.[1] These reactions require energy. One way of categorizing metabolic processes, whether at the cellular, organ or organism level is as 'anabolic' or as 'catabolic', which is the opposite. Anabolism is powered by catabolism, where large molecules are broken down into smaller parts and then used up in respiration. Many anabolic processes are powered by adenosine triphosphate (ATP).

What happens to any material not degraded by the lysosomes?

it is ejected from the cell through exocytosis.

From the purkinje fibres, how the action potential transmitted from one cardiac muscle to the next?

it is spread through gap junctions from the purkinje fibres from one cardiac muscle to the next.

The oxygen dissociation curve shifts ____ in tissues where Hb should load more oxygen.

left

A person weighs _____ at the top of a mountain than at sea level.

less

Since friction is usually a fraction of the normal force, the coefficients of friction generally have a value of :

less than 1. In addition, µs is greater than µk. This makes a heavy object easier to push once it is already moving, compared to trying to push it from rest.

In the postabsorptive state or between meals, 95% of lipids in the plasma are in the form of _______?

lipoproteins: - lipoproteins look like small chylomicrons.

The ability of water to hydrogen bond allows it to maintain its _____ state in the cellular environment.

liquid

Gluconeogenesis, which is the generation of glucose, occurs only in the ?

liver; The liver possesses an enzyme called glucose-6-phosphatase, which dephosphorylates glucose-6-phosphate, converting it into glucose. This enzyme is also found in kidney cells

Where are the Purkinje Fibres located?

located in the inner ventricular walls of the heart, just beneath the endocardium. These fibers consist of specialized cardiomyocytes that are able to conduct cardiac action potentials more quickly and efficiently than any other cells in the heart. Purkinje fibers allow the heart's conduction system to create synchronized contractions of its ventricles, and are therefore essential for maintaining a consistent heart rhythm.

Parasympathetic pre-ganglionic neurons are ____ while post-ganglionic neurons are ____.

long; short

What does adding a non-competitive inhibitor do to the rate of enzyme catalyzed reactions?

lowers Vmax

What are the cells directly involved in innate immunity?

macrophages, neutrophils, eosinophils, basophils, Natural killer cells

The centre of ______ always coincides with the centre of ______, which is the mean location of all the mass in a system

mass; gravity. From outside the system, it can act as if all the mass is concentrated at a single point.

How many nuclei do fungal cells contain?

may have more than 1, they may or may not be identical.

All chordates are Deuterostomes, which means:

meaning that their anus develops from or near the blastopore (A blastopore is an opening into the archenteron during the embryonic stages of an organism. The distinction between protostomes and deuterostomes is based on the direction in which the mouth (stoma) develops in relation to the blastopore)`

At 90°, Fnet=mgsinθ=?

mg

cofactors are either ______ or ______?

minerals or coenzymes; many coenzymes are vitamins or their derivatives

The ____ _____ is made from polar microtubules produced by the centrosome, which connects to kinetochore microtubules at the centromere of each chromosome during meiosis.

mitotic spindle

Proteoglycans:

mixture of proteins and carbs but contain more than 50% carbohydrates. - major component of ECM.

What role do monocytes play in this innate immunity?

monocytes circulate in the blood until they are needed. - They enter the damaged or infected tissue via diapedesis - once inside the tissues, monocytes mature to become macrohpages

Filtrate entering the loop of Henle is expected to be:

more concentrated than filtrate leaving the loop of Henle. - The loop of Henle concentrates the medulla via a net loss of solute from the ascending loop into the medulla.

With the exception of yeast, fungi are ______?

multicellular

The inside of the membrane is ____ with respect to the outside of the membrane.

negative

What are the granulocytes?

neutrophils, eosinophils, basophils

Does decreasing the concentration of the substrate change the rate of an enzyme catalyzed reaction?

no

Is smooth muscle striated?

no

Would the neuroeffector synapse in the sympathetic NS be affected if we used an acetylcholine antagonist?

no

Anaerobic=?

no oxygen used

How is skeletal muscle shaped?

non branched

Which type of bonds allow the substrate to bind to the active site of an enzyme?

noncovalent bonds, like There are four commonly mentioned types of non-covalent interactions: hydrogen bonds, ionic bonds, van der Waals forces, and hydrophobic interactions, forming the enzyme-substrate complex.

How effective are vaccines against rapidly mutating viruses?

not very effective

Smell is called:

olfaction

Secondary structure:

once the primary structure is formed, the singel chain can twist into an alpha-helix, or lie along side itself and form a beta-pleated sheet. Both alpha-helices and beta-pleated sheets are secondary structures and contribute to the conformation of the protein.

What is produced when Acyl CoA is converted into Acetyl CoA?

one NADH and one FADH₂

Where does nutrient and gas exchange occur for any tissue other than vascular tissue?

only across capillary walls, and not across arterioles or venules

Photoheterotroph

organism that is photosynthetic but needs organic compounds as a carbon source - Carbon source is from organic compounds

Chemoautotroph

organism that makes organic carbon molecules from carbon dioxide using energy from chemical reactions - carbon source is CO₂

Chemoheterotroph

organism that must take in organic molecules for both energy and carbon - Carbon source is from organic compounds

Photoautotroph

organism that uses energy from sunlight to convert carbon dioxide and water to carbon compounds - carbon source is CO₂

_________ of Fatty Acids liberates large amounts of chemical energy for the cell.

oxidation

What are the electrons ultimately accepted by at the end of the ETC?

oxygen in order to form water. The final electron acceptor is oxygen.

Aerobic=?

oxygen is used

What must p+q always equal if there are only two alleles?

p+q=1

Membranes are ______ to non-polar molecules?

permeable

What is the pH of a full stomach?

ph = 2

What type of endocytosis is it when the cell takes up solid material?

phagocytosis; only a few specialized cells are capable of this.

A kinase _______ something

phosphorylates

What type of endocytosis is it when the cell takes up liquid?

pinocytosis; liquid is engulfed by small invaginations of the cell membrane. It is non-selective and performed by most cells.

What do the glycosaminoglycans and proteoglycans provide for the ECM?

pliability to the matrix.

What is a first filial or F₁ generation?

the first filial generation seeds/plants or animal offspring resulting from a cross mating of distinctly different parental types. - An example of the first filial or F₁ generation is when purple flowered plants are crossed with white flowered plants, resulting in a purple coloured F₁ generation of plants. - therefore, the purple trait is dominant and the white trait is recessive.

What does fungi release to give rise to new mycelia?

the hyphae release haploid spores that give rise to new mycelia in asexual reproduction. Though spore production is not always due to asexual reproduction.

Which side of the SER membrane are all the phospholipids synthesized?

the phospholipids are all synthesized on the cytosol side of the membrane and then some are flipped to the other side by proteins called phospholipid translocators located exclusively in the SER.

Centripetal Force must be at least one of:

the three forces: gravity, electromagnetic or contact. Most Fc problems on the MCAT can be solved by equating the Fc with the force responsible for it. For example, the gravitational force of the Earth causes the moon to move around it. In this case we simply set the centripetal force equation equal to Newton's gravitational force equation. These two forces are the same force, thus are equal.

How do spores get to new locations suitable for new mycelia growth?

they are taken by the wind, water, or animals

In order to create and AP, the stimulus to the membrane must be greater than the?

threshold stimulus; any stimulus larger than the threshold stimulus creates the same size action potential.

How do osteocytes that are trapped between the lamellae of concentric rings in compact bone exchange nutrients?

through tunnels called canaliculi

Which other lipids are sometimes referred to as fatty acids?

triacylglycerols, phospholipids and glycolipids

What are lipoproteins made from?

triglycerides, cholesterol, phospholipids, and protein.

Chemical synapses are __directional.

unidirectional.. Neurotransmitters travel in one direction across synapse.

What other factors does oxygen saturation depend on?

1. Carbon Dioxide pressure 2. pH 3. Temperature

What does a shift the the left of the Oxygen Dissociation Curve indicate?

An increasing of Hemoglobin's affinity for oxygen - Left shift=more bound O₂

How does an infected cell signal for its own death?

An infected cell signals for its own death by presenting some of the antigen on its surface through the class I MHC molecule and then its destroyed by an activated cytotoxic T cell

Which section of the Nephron contains glucose transporters used to reabsorb all glucose from filtrate?

The proximal convoluted tubule

How is an object's weight determined at the surface of Earth.

An object's weight is given by the product of its mass and the gravitational constant g. F=ma, the weight or force in Newtons of that object on the surface of Earth.

What are the 2 jobs that the normal force has for a mass moving down a curved surface?

1) a portion (mgcosθ) counters some gravitational forces 2) the rest (mv²/r) must create the centripetal acceleration to change the direction of the velocity

What are the 2 major types of filaments in the cytoskeleton?

1) Microfilaments: Microfilaments or actin filaments are the thinnest filaments of the cytoskeleton.These linear polymers of actin subunits are flexible and relatively strong, resisting buckling by multi-piconewton compressive forces and filament fracture by nanonewton tensile forces. Microfilaments are highly versatile, functioning in cytokinesis, amoeboid movement, and changes in cell shape. In inducing this cell motility, one end of the actin filament elongates while the other end contracts, presumably by myosin II molecular motors.[1] Additionally, they function as part of actomyosin-driven contractile molecular motors, wherein the thin filaments serve as tensile platforms for myosin's ATP-dependent pulling action in muscle contraction and pseudopod advancement. 2) Microtubules: These cylindrical polymers of tubulin can grow as long as 25 micrometers and are highly dynamic. The outer diameter of microtubule is about 25 nm. Microtubules are important for maintaining cell structure, providing platforms for intracellular transport, forming the mitotic spindle, as well as other cellular processes.[1] There are many proteins that bind to microtubules, including motor proteins such as kinesin and dynein, severing proteins like katanin, and other proteins important for regulating microtubule dynamics. Microtubules are long, hollow cylinders made up of polymerised α- and β-tubulin dimers. Tubulin dimers polymerize end to end in protofilaments which are the building block for the microtubule structure. Thirteen protofilaments associate laterally to form a single microtubule and this structure can then extend by addition of more protofilaments.

What are the 6 types of glial cells?

1) Microglia 2) Ependymal cells 3) Satellite cells 4) Astrocytes 5) Oligodendrocytes 6) Neurolemmocytes or Schwann Cells

What are the 3 types of molecules with which chemical intercellular communication is accomplished?

1) Neurotransmitters- Nervous system 2) local mediators- paracrine system 3) hormones- endocrine system

What are the 2 types of cholinergic receptors?

1) Nicotinic Receptors: Found in the postsynaptic cells of the synapse between ANS pre-ganglionic and post-ganglionic neurons on skeletal muscle membrane at the neuromuscular junction. 2) Muscarinic Receptors: found on the effectors of the parasympathetic nervous system.

What are the 6 groups of enzymes?

1) Oxidoreductases 2) transferases 3) hydrolases 4) lyases 5) isomerases 6) ligases

What are the 4 primary means of enzymatic regulation?

1) Proteolytic Cleavage- irreversible covalent modification 2) Reversible covalent modification 3) Control Proteins 4) Allosteric Interactions

What are the 2 divisions of the PNS?

1) Somatic NS 2) Autonomic NS - each of these divisions can be further divided into a sensory and a motor portion.

Describe the 4 steps of Spermatogenesis:

1) Spermatogonium (2n) undergo mitosis to become a primary spermatocyte (2n) 2) after meiosis I (genetic diversity via reductional division), a primary spermatocyte (2n) becomes two secondary spermatocytes (n) 3) After meiosis II (equational division), four haploid spermatids (n) are produced which start to grow a flagellum and lose much of their cytoplasm 4) Differentiation and maturation to sperm cells (spermatozoa), which are haploid (n), occurs through out the seminiferous tubules and into the epididymis.

What are the two types of friction?

1) Static Friction: is the force opposing motion when two contiguous surfaces are not moving relative to one another, like tires of a moving care on the pavement. 2) Kinetic Friction: is the force resisting motion once the two contiguous surfaces are sliding relative to one another, like tires of a car sliding on ice.

What are the 4 forces in nature?

1) Strong nuclear force 2) Weak nuclear force 3) Gravitational force 4) Electromagnetic force

What are the 4 phases of the Menstrual Cycle?

1) The Follicular/Proliferative Phase: begins with development of follicle and ends at ovulation 2) Ovulation Phase 3) The Luteal Phase: begins with ovulation and ends with the degeneration of the corpus luteum into the corpus albicans. 4) Flow: The shedding of the uterine lining lasting about 5 days.

What are the 6 steps of Ovulation?

1) The primary oocyte is arrested within a follicle. 2) FSH stimulates the granulosa cells to surround the primary oocyte. The growing follicle contains the granulosa secretion called the Zona pellucida. Theca cells grow around the primary follicle creating the secondary follicle - the growing follicle consists of theca cells surrounding granulosa cells, which surround the zona pellucida and the oocyte. 3) The graffian or secondary follicle is formed. 4) Ovualtion: the follicle ruptures releasing secondary oocyte. - due to rapid estradiol increase and rapid LH increase - secondary oocyte with corona radiata is released into fallopian tubes, 5) Corpus lutem develops from the remnant of the follicle 6) Corpus luteum degenerates to corpus albicans if no egg is fertilized.

What are 5 types of denaturing agents and what forces do they disrupt?

1) Urea- hydrogen bonds 2) salt of pH change- electrostatic bonds 3) Mercaptoethanol- disulfide bonds 4) organic solvents- hydrophobic forces 5) Heat- all forces

What are the steps of viral infection of a host cell?

1) Virus adsorbs to glycoprotein chemical receptor on host cell...attachment to host cell 2) The tail of the virus attaches to the cell wall→ viral enzymes digest a hole in the host cell wall→ penetrates the host cell wall/membrane and injects the viral genetic material (RNA or DNA) into the host cell. 3) Use of host synthetic mechanisms to replicate viral components 4) The self assembly and release of new viral particles.

List the pathway of gas exchange in humans:

1. Air enters the external nares (nostrils) and travels through the nasal passage where it is filtered by nasal hairs and mucous (air also enters through the mouth) 2. Air passes through the pharynx and into the larynx (voice box). to ensure food does not enter the respiratory tract on route to the esophagus, the epiglottis covers the glottis (opening to the larynx). 3. Air passes from the larynx into the cartilaginous trachea 4. Air passes into two bronchi, left and right, which enter the lungs. 5. Bronchi further divide into bronchioles 6. Each bronchiole is surrounded by clusters of small air sacs called alveoli- this is where gas exchange occurs 7. Each alveolus is coated by surfactant which lowers the surface tension of the alveoli and facilitates gas exchange across the membrane 8. Alveoli increase the overall surface area available for gas exchange (O₂ and CO₂) with the pulmonary capillary beds.

What are the 4 parts of the large intestine, or colon?

1. Ascending colon 2. Transverse colon 3. Descending colon 4. Sigmoid colon

What are the main functions of the liver?

1. Blood Storage: the liver can expand to act as a blood reservoir for the body. 2. Blood Filtration: The Kupfer cells of the liver phagocytize bacteria picked up from the intestines. 3. Carbohydrate Metabolism: The liver maintains normal blood glucose levels through gluconeogenesis (production of glycogen and glucose from noncarbohydrate precursors), glycogenesis, and storage of glycogen. 4. Fat Metabolism: the liver synthesizes bile from cholesterol and converts carbohydrates and proteins into fat. It oxidizes fatty acids for energy, and forms most lipoproteins. 5. Protein Metabolism: The liver deaminates amino acids, forms urea from ammonia in the blood, synthesizes plasma proteins such as fibrinogen, prothrombin, albumin, and most globulins, and synthesizes nonessential amino acids. 6. Detoxification: Detoxified chemicals are excreted by the liver as part of bile or polarized so they may be excreted by the kidney. 7. Erythrocyte Destruction: Kupfer cells also destroy irregular erythrocytes, but most irregular erythrocytes are destroyed by the spleen. 8. Vitamin Storage: the liver stores vitamins such as vitamins A, D, and D₁₂. The liver also stores iron combining it with the protein apoferritin to form ferritin.

What are the 8 main functions of the liver?

1. Blood storage 2. Blood filtration 3. Carbohydrate metabolism 4. Fat metabolism 5. Protein metabolism 6. Detoxification of chemicals 7. Erythrocyte destruction 8. Vitamin storage

What are the 3 metabolic fates of amino acids in the liver?

1. Can be used by liver or other cells for protein translation 2. Can be deaminated to produce pyruvic acid, acetyl CoA, or other Krebs cycle intermediates for energy metabolism. This creates ammonia.... 3. Can be converted into fat for for storage within the liver.

What are the 2 types of smooth muscle?

1. Single Unit 2. Multi-unit

What are the 3 types of muscle tissue?

1. Skeletal 2. Cardiac 3. Smooth

What does innate immunity include?

1. Skin as a barrier to organisms and toxins 2. stomach acid and digestive enzymes to destroy ingested organisms and toxins 3. phagocytotic cells 4. chemicals in the blood

What are the 2 ways in which fluid is propelled through the lymphatic system?

1. Smooth muscle in the walls of the larger lymph vessels contracts when stretched 2. The lymph vessels may be squeezed by adjacent skeletal muscles, body movements, arterial pulsations, and compression from objects outside the body.

What does a shift the the right of the Oxygen Dissociation Curve indicate?

A lowering of Hemoglobin's affinity for oxygen - Right shift= less bound O₂

Weight:

A measure of the gravitational force exerted on an object; its value can change with the location of the object in the universe. In other words, it is the gravitational force that an object experiences when near a much larger body such as Earth. Weight is measured in Newtons (N).

Why is the concentration of the medulla with solute so important to the function of other parts of the nephron?

A medulla with high concentration of solute allows for the passive absorption of water from the filtrate in other areas of the nephron, thus conserving water in the body and concentrating the urine.

What happens when amphipathic molecules like phospholipids are placed in aqueous solution?

A micelle is formed.The molecules spontaneously aggregate, turning their polar heads to the solution and their non-polar fatty acid chains toward each other. This results in a spherical micelle.

What is the zygote called when it is composed of 8 or more cells after cleavage takes place?

A morula; the embryo at this stage does not grow during cleavage.

What are vaccines?

A vaccine can either be: 1) an injection of antibodies, or 2) an injection of a non-pathogenic virus with the same capsid or envelope as the pathogenic virus. This allows the body to form its own antibodies

What is the key hormone involved in the Renin-Angiotensin System, and what does it do?

Aldosterone is the key mineral corticoid involved in the RAS. - aldosterone acts in the distal convoluted tubules and collecting ducts of the kidney to increase Na⁺ and cl⁻ reabsorption and K⁺ and H⁺ secretion. - This process creates a net gain of plasma particles which increases blood volume and pressure.

What happens after menarche (a women's first period)?

After menarche, one primary oocyte per month completes meiosis I (reductional division) during ovulation, yielding two daughter cells of unequal size: a secondary oocyte (n) and a small polar body.

How is myosin an ATPase?

After myosin binds to actin and pulls the actin filament along, creating the muscle contraction, ATP binds to myosin releasing it from the actin filament. - Myosin immediately hydrolyzes the ATP using the energy to return to its ready and high energy position.

The ____ is the muscle that is responsible for the movement; while the ___ is the muscle is the muscle that stretches.

Agonist; antagonist

Where are most of the plasma proteins formed?

Albumin, fibrinogen and most other plasma proteins are formed In the liver

______ is the major osmoregulatory protein in the blood.

Albumin: Albumin is the main protein of plasma; it binds water, cations (such as Ca2+, Na+ and K+), fatty acids, hormones, bilirubin, thyroxine (T4) and drugs (including barbiturates) - its main function is to regulate the colloidal osmotic pressure of blood. Alpha-fetoprotein (alpha-fetoglobulin) is a fetal plasma protein that binds various cations, fatty acids and bilirubin. Vitamin D-binding protein binds to vitamin D and its metabolites, as well as to fatty acids. The biological role of afamin (alpha-albumin) has not yet been characterized.

What effect does aldosterone have and on which segment of the Nephron?

Aldosterone acts on the distal tubule to increase sodium and potassium membrane transport proteins, therefore increasing the reabsorption of both.

What other effects does aldosterone have on the body?

Aldosterone also causes systemic vasoconstriction, enhanced NT release, and stimulation of ADH/vaspressin release. - ALdosterone also tells the brain to cause thirst

How does aldosterone affect blood pressure?

Aldosterone creates a net gain of ions and particles in the blood plasma, which results in an eventual increase in blood pressure. This is also known as the Renin-Angiotensin system, - has the same effect, to a lesser extent, on sweat glands, salivary glands and the intestines.

What is an autosomal chromosome?

An autosome is a chromosome that is not an allosome (i.e., not a sex chromosome).[1] Autosomes appear in pairs whose members have the same form but which differ from other pairs in a diploid cell, whereas members of an allosome pair may differ from one another and thereby determine sex. For example, in humans there are typically 22 pairs of autosomes and one allosome pair. The allosome pair consists of two X chromosomes (female) or one X and one Y chromosome (male). (Unusual combinations are XYY, XXY, XXX, XXXX, XXXXX or XXYY, among other allosome combinations, are known to occur. These generally cause developmental abnormalities.) The autosome pairs are labeled with numbers (1-22 in humans), and allosomes are labeled with their letters. - Every person has two copies of every gene on autosomal chromosomes, one from mother and one from father. If a genetic trait is recessive, a person needs to inherit two copies of the gene for the trait to be expressed. Thus, both parents have to be carriers of a recessive trait in order for a child to express that trait.

How does the ETC work?

An electron transport chain (ETC) couples electron transfer between an electron donor (such as NADH) and an electron acceptor (such as O2) with the transfer of H+ ions (protons) across a membrane. The resulting electrochemical proton gradient is used to generate chemical energy in the form of adenosine triphosphate (ATP). Electron transport chains are the cellular mechanisms used for extracting energy from sunlight in photosynthesis and also from redox reactions, such as the oxidation of sugars (respiration). As electrons are passed along, protons are pumped into the intermembrane space for each NADH. This establishes the proton gradient called the proton-motive force which propels protons through ATP synthase to manufacture ATP.

Since each villus is composed of many cells, what is a single Villus cell called?

An enterocyte

Lock and Key Theory:

An example of enzyme specificity: the active site of the enzyme has a specific shape that only fits a specific substrate.

What is the general principle of cell signalling and secondary messengers?

An external signalling molecule binds to a receptor on the cell and triggers an internal cell signalling pathway that is amplified and results in a cellular response.

Glucagon and Insulin act ________ to each other.

Antagonistically

The adenohypophysis is also known as the?

Anterior Pituitary; and is located in the brain, beneath the hypothalamus

Where is the gall bladder located?

Anterior to the liver

What is the newly formed cavity of the gastrula called?

Archenteron: - will later develop into the gut.

_____ that block translation by prok ribosomes but not euk ribosomes, also block translation by mitochondrial ribosomes.

Antibiotics; - this tells us that translation in both proks and mitochondria are very similar, implying an evolutionary relation

______ consist of gamma globulin proteins of two large heavy chains and two small light chains.

Antibodies - The constant region remains virtually unchanged - The variable region is able to recognize a specific epitope on an antigen

______ ______, also called vasopressin, is a small posterior pituitary peptide hormone that causes the collecting ducts of the kidney to become permeable to water, thus allowing the body to reabsorb water from the urine. This reduces the volume of urine and concentrates the urine.

Antidiuretic Hormone

What is the portion of an antigen that binds to an antibody called?

Antigenic Determinant:

Who can a person with type AB blood receive blood from?

Anyone; they are the universal recipient

Oxygenated blood leaves the heart via the ____.

Aorta

What is an enzyme without its cofactor called?

Apoenzyme; is completely non-functional

How is the process of apoptosis regulated in humans?

Apoptosis is regulated by protein activity as opposed to regulation at the transcription level or translation level. The proteins involved in apoptosis are present but inactive in a normal healthy cell.

Part of normal cell development is programmed cell death or _______.

Apoptosis: - Apoptosis is essential for development of the nervous system, operation of the immune system, and destruction of tissue between fingers and toes to create normal hands and feet in humans.

How often does the menstrual cycle repeat itself?

Approximately every 28 days after puberty unless pregnancy occurs. - with each menstrual cycle, several primordial oocytes may begin the process. but, normally, only one completes the development to ovulation.

What is the important thing to know considering fungal reproduction?

Asexual reproduction occurs when conditions are good; sexual reproduction occurs when the conditions are tough. This is because if the conditions are good for the parent, they will be good for the asexually reproducing offspring that are exactly like the parent, but if conditions are bad for the parent, they may not be bad for sexually reproduced offspring that are genetically different from the parent.

What are the 2 acidic aa?

Aspartic acid and glutamic acid

_______ is a commonly used inhibitor of the synthesis of prostaglandins in order to reduce inflammation caused by prostaglandins.

Aspirin

How does aspirin work on the body?

Aspirin inhibits prostaglandin synthesis and thus is an anti-inflammatory.

____ are star-shaped neuroglia in the CNS that give physical support to neurons, and help maintain the mineral and nutrient balance in the interstitial space.

Astrocytes: - The most abundant type of macroglial cell, astrocytes (also called astroglia) have numerous projections that anchor neurons to their blood supply. They regulate the external chemical environment of neurons by removing excess ions, notably potassium, and recycling neurotransmitters released during synaptic transmission. The current theory suggests that astrocytes may be the predominant "building blocks" of the blood-brain barrier. Astrocytes may regulate vasoconstriction and vasodilation by producing substances such as arachidonic acid, whose metabolites are vasoactive.

How are membrane proteins distributed throughout the membrane?

Asymmetrically, and proteins nor lipids flip easily in the membrane

At birth, all bone marrow is ___, but with age, more of it is converted to the ____ type.

At birth, all bone marrow is red, but with age, more of it is converted to the yellow type.

What do Lymphoid stem cells mature into?

B and T cells/lymphocytes

What is the clump of chewed food mixed with saliva called?

Bolus

What are the functions of bones?

Bone functions to support soft tissue, protect internal organs, assist in movement of the body, store minerals like calcium, blood cell production, and energy storage in the form of adipose cells in the bone marrow.

Erythrocytes lose their nucleus while still in the ____ ____.

Bone marrow

Both ____ and _____ are prokaryotes, though ______ have similarities to Eukaryotes

Both Archaea and Bacteria are prokaryotes, though Archaea have similarities to Eukaryotes

Describe how the T3 and T4 hormones enter the cell?

Both T3 and T4 hormones are lipid soluble tyrosine derivatives that diffuse through the lipid bilayer and act in the nucleus of the cells of their effector, thus influencing gene expression.

What type of gland does the pancreas act as?

Both an exocrine, as it releases digestive enzymes through the pancreatic duct into the digestive tract (which is the external environment), and as an endocrine gland, as it releases insulin and glucagon directly into the blood.

Which distances act at a distance?

Both gravitational and electromagnetic

How does Bowman's Capsule assist in clearing urea from the blood?

By allowing urea to diffuse into the filtrate under filtration pressure because the only process available for the removal of wastes by the Bowman's capsule is diffusion, aided by the hydrostatic pressure of blood.

How do minerals assist in the transport of substances entering and exiting the cell?

By creating an electrochemical gradient.

How could you increases the rate of reaction in the presence of a competitive inhibitor?

By increasing the concentration of the substrate. Overcoming inhibition by increasing the concentration of the substrate is the classic indication of competitive inhibition. Competitive inhibitors often resemble the substrate. Competitive inhibitors raise the apparent Km but do not change Vmax.

Given the masses of two objects orbiting each other, how would you find the instantaneous velocity of either one?

By making Fc equal to Fg and solve. Fc=Fg =mv²/r=GMm/r²

Where are red blood cells formed?

By stem cells in the bone marrow

Through which section of the Nephron are drugs, toxins and other solutes secreted into the filtrate?

By the cells of the proximal tubule.

Where is the ECM formed?

By the cells that it surrounds

How are lipoproteins classified?

By their density: The greater the ratio of lipid to protein, the lower the density because proteins are far more dense than lipids.

How does blood regulate the extracellular environment of the body?

By transporting nutrients, waste products, hormones, heat, and cells of the immune response.

Food in the upper duodenum, especially fat digestates, cause the release of ________, and what is the result?

Cholecystokinin: - causes gall bladder contraction and pancreatic enzyme secretion. It also decreases the motility of the stomach.

_____ is the phylum containing humans.

Chordata: - does not mean backbone - all chordates have bilateral symmetry

____ are the structural units of genetic material consisting of a single, double-stranded DNA molecule and its associated proteins.

Chromosomes

What are the major classes of Lipoproteins in humans?

Chylomicrons, VLDL, LDL and HDL

Once in the stomach, the bolus becomes a mixture of fluid and food called _____?

Chyme

_____ have a whip like movement causing the fluid to move laterally.

Cilia

The Krebs Cycle is also known as the?

Citric Acid Cycle

What class do all mammals belong to?

Class: Mammalia

What is cleavage and when does it takes place?

Cleavage is the mitotic division without differentiation. Cleavage is the division of cells in the early embryo. The zygotes of many species undergo rapid cell cycles of mitosis with no significant growth, producing a cluster of cells the same size as the original zygote. The different cells derived from cleavage are called blastomeres and form a compact mass called the morula. Cleavage ends with the formation of the blastula. - cleavage occurs in the fallopian tube after fertilization.

What does the pancreatic enzyme, carboxypolypeptidase do?

Cleaves amino acids from the sides of the peptides being degraded by trypsin and chymotrypsin. - hydrolyzes terminal peptide bonds at carboxyl end and converted to active form by trypsin.

When blood glucose levels decrease, ______ takes place in the liver, and glucose is returned to the blood.

Gycogenolysis: the breakdown of glycogen to glucose

Summarize the immune response:

For a Bacterial Infection: Humoral/B cell immunity: - Inflammation - Macrophages then neutrophils move in to engulf bacteria - Interstitial fluid is flushed into the lymphatic system where lymphocytes wait in the lymph nodes - Macrophages process and present the the bacterial antigens to B lymphocytes - B lymphocytes with the help from Helper T cells are able to differentiate into into Memory B cells and plasma cells - plasma cells produce free antibodies and mast cell bound antibodies - Memory B cells remain in blood in preparation for a secondary infection

How can a substance reach the cytosol or ER lumen?

For a substance to reach the cytosol, it must cross the cell membrane via passive or facilitated diffusion, or active transport, but it can reach the ER lumen via endocytosis without ever transporting across a membrane.

What does cytoplasmic streaming allow?

For rapid growth

Steroids:

Four ringed structures, that include some hormones, vitamin D and cholesterol, an important membrane component.

Fovea = Greatest ____ ____

Fovea = greatest vision acuity.

Describe the G-protein coupled receptor system:

G protein coupled receptors (GPCRs), also known as seven-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-linked receptors (GPLR), comprise a large protein family of transmembrane receptors that sense molecules outside the cell and activate inside signal transduction pathways and, ultimately, cellular responses. G protein-coupled receptors are found only in eukaryotes. The ligands that bind and activate these receptors include light-sensitive compounds, odors, pheromones, hormones, and neurotransmitters, and vary in size from small molecules to peptides to large proteins. G protein-coupled receptors are involved in many diseases, and are also the target of approximately 40% of all modern medicinal drugs. There are two principal signal transduction pathways involving the G protein-coupled receptors: the cAMP signal pathway and the phosphatidylinositol signal pathway. When a ligand binds to the GPCR it causes a conformational change in the GPCR, which allows it to act as a guanine nucleotide exchange factor (GEF). The GPCR can then activate an associated G-protein by exchanging its bound GDP for a GTP. The G-protein's α subunit, together with the bound GTP, can then dissociate from the β and γ subunits to further affect intracellular signaling proteins or target functional proteins directly depending on the α subunit type

How is galactose absorbed?

Galactose follows a similar absorption path to glucose, via symport secondary active transport system (SGLT1)

Through which type intra-cellular junctions are cardiac contraction signals spread?

Gap Junctions

___ ___ are small tunnels connecting cells.

Gap Junctions: - they allow small molecules and ions to move between cells. - crucial for cell to cell communication - gap junctions in cardiac muscle provide for the spread of the action potential from cell to cell. - gap junctions allow the direct sharing of cytoplasm between cells.

___ ____ peptide is released in response to fat and protein digestates in the duodenum, and to a lesser extent, in response to carbohydrates.

Gastric Inhibitory - has a mild effect in decreasing motor activity of the stomach.

Formation of the germ layers?

Gastrulation

_________ is a phase early in the embryonic development of most animals, during which the single-layered blastula is reorganized into a trilaminar ("three-layered") structure known as the gastrula. These three germ layers are known as the ectoderm, mesoderm, and endoderm.

Gastrulation: - Gastrulation takes place after cleavage and the formation of the blastula and primitive streak. Gastrulation is followed by organogenesis, when individual organs develop within the newly formed germ layers. Each layer gives rise to specific tissues and organs in the developing embryo. The ectoderm gives rise to epidermis, and to the neural crest and other tissues that will later form the nervous system. The mesoderm is found between the ectoderm and the endoderm and gives rise to somites, which form muscle; the cartilage of the ribs and vertebrae; the dermis, the notochord, blood and blood vessels, bone, and connective tissue. The endoderm gives rise to the epithelium of the digestive system and respiratory system, and organs associated with the digestive system, such as the liver and pancreas. Following gastrulation, cells in the body are either organized into sheets of connected cells (as in epithelia), or as a mesh of isolated cells, such as mesenchyme.

The ____ ___ is the total of all alleles in a population.

Gene pool

What is a monohybrid cross usually used for?

Generally, the monohybrid cross is used to determine the F2 generation from a pair of homozygous grandparents (one grandparent dominant, the other recessive) which results in an F1 generation that are all heterozygous. Crossing two heterozygous parents from the F1 generation results in an F2 generation that produces a 75% chance for the appearance of the dominant phenotype, of which two-thirds are heterozygous, and a 25% chance for the appearance of the recessive phenotype. This cross was originally used by biologist, Gregor Mendel, who crossed two pea plants to obtain a hybrid variety, discovering the possible changes in phenotypes of various alleles.

____ are the actual units of heredity that are located on chromosomes.

Genes

When undergoing physical exercise, healthy adult skeletal muscle is likely to respond with an increase in what?

Glycolysis, CAC, and Protein production

Which hypothalamus hormone stimulates the anterior pituitary to release LH? and what stimulates the hypothalamus to release this hormone?

Gonadotropin Releasing hormone, GnRH, is released from the hypothalamus to the anterior pituitary gland after the hypothalamus is stimulated by estrogen.

Which hypothalamus hormone stimulates the anterior pituitary to release FSH?

Gonadotropin Releasing hormone; GnRH, which is itself stimulated for release by estrogen.

Will the bacteria be gram positive or negative if it has a thin PD cell wall?

Gram Negative and will look pink because most of the dye will wash off. - There is a phospholipid bilayer on the outer side of the PD layer, which is different from gram + bacteria.

Which type of bacteria are more antibiotic resistant and why?

Gram Negative tend to be more resistant to antibodies and antibiotics because of a protective barrier created by polysaccharide chains that protrude from the outer phospholipid bilayer.

What do bacteria used to stick themselves to solid surface, and which type of bacteria possess these?

Gram negative bacteria possess fimbriae or pili, which are short tentacles, usually numbering in the thousands, and can attach a bacterium to a solid surface. Not involved in cell motility or bacteria sex.

What are the granular leukocytes?

Granulocytes are named based on their staining properties Neutrophils, Eosinophils and basophils

What is the life of a granulocyte like?

Granulocytes remain in the blood for 4 to 8 hours before they are deposited in the tissues, where they live for 4 to 5 days.

An individual exposed to a pathogen for the first time will exhibit an innate immune response involving:

Granulocytes: neutrophils, basophils and Eosinophils

How do you identify electromagnetic forces and gravitational forces?

Gravity is usually just mg Electromagnetic forces require a charged object or a magnet. In order for any other force to be acting on the system, something must be making visible contact with the system.

The greater the pressure of carbon dioxide, the _____ the blood content of carbon dioxide.

Greater

Which hypothalamus hormone stimulates the anterior pituitary to release hGH?

Growth Hormone Releasing Hormone (GHRH)

What is the Bohr Effect?

Hemoglobin's oxygen binding affinity is inversely related both to acidity and to the concentration of carbon dioxide. That is to say, a decrease in blood pH or an increase in blood CO₂ concentration will result in hemoglobin proteins releasing their loads of oxygen and a decrease in carbon dioxide or increase in pH will result in hemoglobin picking up more oxygen. Since carbon dioxide reacts with water to form carbonic acid, an increase in CO2 results in a decrease in blood pH. - This effect facilitates oxygen transport as hemoglobin binds to oxygen in the lungs, but then releases it in the tissues, particularly those tissues in most need of oxygen. When a tissue's metabolic rate increases, its carbon dioxide production increases. - Although the reaction usually proceeds very slowly, the enzyme family of carbonic anhydrase, which is present in red blood cells, accelerates the formation of bicarbonate and H⁺ ions. This causes the pH of tissues to decrease, and so, promotes the dissociation of oxygen from hemoglobin to the tissue, allowing the tissue to obtain enough oxygen to meet its demands. - Conversely, in the lungs, where oxygen concentration is high, binding of oxygen causes hemoglobin to release protons, which combine with bicarbonate to drive off carbon dioxide in exhalation. Since these two reactions are closely matched, there is little change in blood pH. The dissociation curve shifts to the right when carbon dioxide or hydrogen ion concentration is increased. This facilitates increased oxygen dumping. This mechanism allows for the body to adapt the problem of supplying more oxygen to tissues that need it the most. When muscles are undergoing strenuous activity, they generate CO2 and lactic acid as products of cellular respiration and lactic acid fermentation. In fact, muscles generate lactic acid so quickly that pH of the blood passing through the muscles will drop to around 7.2. As lactic acid releases its protons, pH decreases, which causes hemoglobin to release ~10% more oxygen.

____ consists of 4 globular protein subunits, each connected to a prosthetic heme group.

Hemoglobin: - the globular protein has 2 beta chains and 2 alpha chains. = each chain has a heme group, each heme group is capable of binding one molecule of oxygen (O₂) - the Fe in the heme group is what associates with the oxygen molecule.

Within which type of bone does Hemopoiesis occur?

Hemopoiesis is the production of red blood cell. This occurs inside the red bone marrow contained in spongy bone. Platelets and most white blood cells also arise in red bone marrow

Through which artery is oxygenated blood received by the liver?

Hepatic Artery

Through which vein does deoxygenated blood enter the Liver?

Hepatic Portal Vein

Colourblindness is a sex-linked recessive trait. A woman is born colour-blind. What can be said with certainty?

Her father and son are colourblind

Are Fungi autotrophs or heterotrophs?

Heterotrophs

What effect does high concentrations of glucagon have on adipose tissue?

High concentrations of glucagon breaks down adipose tissue increasing the fatty acid level of the blood.

Describe HDL and its role in the body:

High-density lipoprotein (HDL) is one of the five major groups of lipoproteins, which, in order of sizes, largest to smallest, are chylomicrons, VLDL, IDL, LDL, and HDL, which enable lipids like cholesterol and triglycerides to be transported within the water-based bloodstream. In healthy individuals, about thirty percent of blood cholesterol is carried by HDL. Blood tests typically report HDL-C level, i.e. the amount of cholesterol contained in HDL particles. It is often contrasted with low-density or LDL cholesterol or LDL-C. HDL particles are able to remove cholesterol from within artery atheroma and transport it back to the liver for excretion or re-utilization, which is the main reason why the cholesterol carried within HDL particles (HDL-C) is sometimes called "good cholesterol" (despite the fact that it is exactly the same as the cholesterol in LDL particles). Those with higher levels of HDL-C seem to have fewer problems with cardiovascular diseases, while those with low HDL-C cholesterol levels (less than 40 mg/dL or about 1 mmol/L) have increased rates for heart disease. While higher HDL levels are correlated with cardiovascular health, no incremental increase in HDL has been proven to improve health. In other words, while high HDL levels might correlate with better cardiovascular health, specifically increasing one's HDL might not increase cardiovascular health. Additionally, those few individuals producing an abnormal, apparently more efficient, HDL ApoA1 protein variant called ApoA-1 Milano, have low measured HDL-C levels yet very low rates of cardiovascular events even with high blood cholesterol values.

What are some of the causative agents of inflammation that are released by tissues?

Histamine, prostaglandins and lymphokines

What is an enzyme with its cofactor called?

Holoenzyme; completely functional

What is the function of the Kidney?

Homeostasis

What are homologous chromosomes?

Homologous chromosomes (also called homologs or homologues) are chromosome pairs of approximately the same length, centromere position, and staining pattern, with genes for the same characteristics at corresponding loci. One homologous chromosome is inherited from the organism's mother; the other from the organism's father.[1] They are usually not identical, but carry the same type of information.

What does homozygous refer to?

Homozygous refers to two alleles on a homologous pair of chromosomes being the same - A cell is said to be homozygous for a particular gene when identical alleles of the gene are present on both homologous chromosomes.[2] The cell or organism in question is called a homozygote. True breeding organisms are always homozygous for the traits that are to be held constant.

This hormone is also known as somatotropin. It is a direct peptide hormone and it stimulates growth in almost all cells of the body.

Human Growth Hormone (hGH) - hGH has no specific target tissue.

Where are large amounts of Type II A fibres found?

In the Upper legs

Describe Humoral or B-cell Immunity and how it works:

Humoral/B-cell Immunity is promoted by B lymphocytes - Each B lymphocyte is capable of making a single type of antibody or immunoglobulin, which it displays on the surface of its plasma membrane. - antibodies recognize foreign particles called antigens - the portion of an antibody that binds to an antigen is highly specific for that antigen. - the portion of the antigen that binds to the antibody is called an Antigenic determinant. - Haptens are an antigenic determinant that has been removed from the antigen - the hapten can only elicit an immune response if the body had been previously exposed to the full antigen. - When a macrophage engulfs a microbe, the macrophage presents the antigenic determinant of that microbe on its cell surface. - If the B lymphocyte antibody contacts a matching antigen that is on the surface of one of these macrophages, the B lymphocyte, assisted by a helper T-cell, will differentiate into plasma cells and memory B-cells. - the plasma cells then begin to synthesize free antibodies and release them into the blood - These free antibodies may attach their bases to Mast cells. - When an antibody, whose base is bound to a mast cell, also binds an antigen, the mast cell releases histamine and other chemicals. - when other free antibodies contact the specific antigen, they bind to it - once bound, the antibodies may begin a cascade of reactions involving blood proteins (called complement) that cause the antigen bearing cell to be perforated - the antibodies may also mark the antigen for phagocytosis by macrophages and NK cells - the antibodies may cause the antigenic substances to agglutinate or even precipitate, or, in the case of a toxin, the antibodies may block its chemically active portion.

_____ _____ in the duodenum causes secretin release. Secretin then stimulates the release of sodium bicarbonate from the pancreas into the duodenum to increase pH.

Hydrochloric acid

What type of bond joins the two strands of a double helix?

Hydrogen bonds

What is the main force between water molecules in liquid water?

Hydrogen bonds- provide strong cohesive forces between water molecules. These cohesive forces squeeze hydrophobic molecules away from water and cause them to aggregate.

What is the major reaction involved in the digestion of all macromolecules?

Hydrolysis

What is the most common catabolic reaction in the human body?

Hydrolysis

____________ molecules dissolve easiest in water, why?

Hydrophilic molecules dissolve easiest in water because their negatively charged ends attract the positively charged hydrogens of water, and their positively charged ends attract the negatively charged oxygen atoms of water..

Although osmotic pressure remains relatively constant through out the capillary, what happens to hydrostatic pressure?

Hydrostatic pressure drops from the arteriole end of the capillary to the venule end of the capillary.... Thus, osmotic pressure overcomes hydrostatic pressure near the venule end of a capillary, and net fluid flow is into the capillary and out of the interstitium. - Remember that the capillary lies between the arterioles and the venules... it is the place of fluid, nutrient and gas exchange.

As blood flows into a capillary, _____ pressure is greater than _____ pressure and a net flow of fluid occurs out of the capillary and into the interstitium.

Hydrostatic pressure is greater than osmotic pressure.

Define Hydrostatic Pressure:

Hydrostatic pressure is the pressure exerted by a fluid at equilibrium due to the force of gravity

The amount of filtrate is related to the ___ ___ of the glomerulus

Hydrostatic pressure of the glomerulus

How do Hydroxyapatite crystals give the bones greater compressive strength?

Hydroxyapatite crystals lie alongside the collagen fibres, and give the bone better compressive strength than the best reinforced concrete.

What is the increase in muscle cell diameter and change in muscle conformation called?

Hypertrophy: is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It should be distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.

The _____ is considered the Master Gland of the endocrine system.

Hypothalamus

What is secreted into the urine/filtrate of the nephron in the Distal Convoluted Tubule?

H⁺, K⁺, HCO₃⁻

What is the I Band of a sarcomere?

I-band is the zone of thin filaments (actin) that is not superimposed by thick filaments. - this is also the region between neighbouring sarcomere units and the Z-band.

How many strands exist in typical RNA and what replaces thymine?

In RNA there is 1 strand and uracil replaces thymine.

Where are NTs stored in a chemical synapse?

In a chemical synapse, small vesicles filled with neurotransmitters rest just under the pre-synaptic membrane.

Describe how the iris reacts in both dark and light environments:

In a dark environment, the sympathetic NS contracts the iris dilating the pupil and allowing more light to enter the eye. In a light environment, the Parasympathetic NS contracts the circular muscles of the iris constricting the pupil and screening out light.

Which cells are capable of absorbing glucose in the absence of insulin?

In the absence of insulin, only neural and hepatic cells are capable of absorbing sufficient amounts of glucose via the facilitated transport system.

Where is glycogen found in the body?

In large amounts in liver and muscle cells, though it is found in all cells of the body.

Where is most of the glycogen stored in the human body?

In liver and skeletal muscle

What is the byproduct of gluconeogenesis from proteins?

In other words, as glucose is created from protein, ammonia, a nitrogen containing compound is the main by-product. This is deamination: - nearly all ammonia is converted to urea by the liver and then excreted in the urine by the kidney.

What happens to the gastrula in the 3rd week after fertilization?

In the 3rd week after fertilization, the gastrula develops into a neurula in a process called neurulation.

Where are steroid hormones synthesized?

In the Smooth ER

Where are steroid hormones formed?

In the Smooth ER and the mitochondria.

Where to B-cells mature into B-Lymphocytes?

In the bone marrow

Where do B-lymphocytes mature and differentiate?

In the bone marrow and the liver

Where does gas exchange between blood and tissues occur?

In the capillaries

For a ring with uniform density has a centre of mass located where?

In the circumscribed centre, a point where there is no mass.

Where does glycolysis take place in living cells?

In the cytosol

In which direction does an electrical gradient point?

In the direction that a positively charged particle will tend to move.

Where are the sensory neuron cell bodies located?

In the dorsal root ganglion, just outside the dorsal horn.

Where does the most chemical digestion of food occur in humans?

In the duodenum

Where do the spermatozoa acquire motility?

In the epididymis

Where are cilia found in humans?

In the fallopian tubes and respiratory tract.

Where does the majority of carbohydrate absorption occur?

In the ileum and jejunum.

Where does the ETC occur?

In the inner membrane of the mitochondria

Where are most lipoproteins made?

In the liver

Where are the gamma globulins that constitute antibodies formed?

In the lymph tissue

Where does the Krebs cycle occur?

In the mitochondrial matrix

Where is pyruvate converted to Acetyl CoA?

In the mitochondrial matrix

Where are carbohydrates digested?

In the mouth and in the small intestine!

Where is the dermis thickest?

In the palms and soles

Where are large amounts of Type I fibres found?

In the postural muscles.

What happens to the collecting duct in the presence of ADH?

In the presence of anti-diuretic hormone, the collecting duct becomes permeable to water, allowing it to passively diffuse into the medulla, concentrating the urine.

What occurs in the presence of Insulin?

In the presence of insulin, - carbohydrates are stored as glycogen in the liver and muscles - fat is stored in adipose tissue - amino acids are taken up by the cells of the body and made into proteins.

Cardiac muscle is excited by?

Increased cytosolic calcium concentration.. that is because all muscles contract in response to increased cytosolic calcium concentrations.

Where does the production of sperm take place?

In the seminiferous tubules of the testes.

Where are large amounts of Type II B fibres found?

In the upper arms

Where do amino acids differ from each other?

In their side chains, designated as the R-groups

What contributes to most of the diffusion of polar or charged molecules across a natural membrane?

Incidental holes or leakage channels created by irregular shapes of integral proteins.

In cases of ______ dominance, the dominant allele does not completely mask the effects of the recessive allele. The heterozygous individual shows an intermediate phenotype that is a blend of the homozygous dominant and homozygous recessive phenotypes.

Incomplete dominance

Since blood volume flow rate is approximately constant, the blood velocity is _____ proportional to the cross-sectional area. Explain:

Inversely proportional: - The greater the cross sectional area, the slower the velocity of the blood. - Thus, since capillaries have the greatest cross sectional area, blood velocity is slowest through capillaries.

Is smooth muscle involuntary or voluntary?

Involuntary

The ANS is ______, where as the SNS is ____.

Involuntary; voluntary

Describe the shape and composition of irregular bones:

Irregular bones have an irregular shape and variable amounts of compact and spongy bone

Agents which bind covalently to enzymes and disrupt their function are:

Irreversible inhibitors - tend to be highly toxic, Penicillin

Glycogen:

Is a branched glucose polymer with α-linkages. - Glycogen is a branched biopolymer consisting of linear chains of glucose residues with further chains branching off every ten glucoses or so. Glucoses are linked together linearly by α(1→4) glycosidic bonds from one glucose to the next. Branches are linked to the chains they are branching off from by α(1→6) glycosidic bonds between the first glucose of the new branch and a glucose on the stem chain.

Fermentation:

Is anaerobic respiration. It includes the process of glycolysis, the reduction of pyruvate to ethanol or lactic acid, and the oxidation of the NADH back to NAD+.

Friction:

Is caused by the attractive molecular forces between contiguous surfaces. Friction opposes the relative motion between contiguous surfaces.

Quaternary Structure:

Is formed when two or more polypeptide chains bind together. The same five forces at work in the 3° structure are at work in the 4° structure.

Describe LDL and its role in the body:

Low-density lipoprotein (LDL) is one of the five major groups of lipoproteins, which in order of size, largest to smallest, are chylomicrons, VLDL, IDL, LDL, and HDL, that enable transport of multiple different fat molecules, including cholesterol, within the water around cells and within the water-based bloodstream. Studies have shown that higher levels of type-B LDL particles (as opposed to type-A LDL particles) promote health problems and cardiovascular disease, they are often informally called the bad cholesterol particles, (as opposed to HDL particles, which are frequently referred to as good cholesterol or healthy cholesterol particles) - When a cell requires cholesterol, it synthesizes the necessary LDL receptors, and inserts them into the plasma membrane. The LDL receptors diffuse freely until they associate with clathrin-coated pits. LDL particles in the blood stream bind to these extracellular LDL receptors. The clathrin-coated pits then form vesicles that are endocytosed into the cell. After the clathrin coat is shed, the vesicles deliver the LDL and their receptors to early endosomes, onto late endosomes to lysosomes. Here the cholesterol esters in the LDL are hydrolysed. The LDL receptors are recycled back to the plasma membrane.

Heavy exercise causes what?

Lowered blood pH Raised CO₂ tension Increased blood temperature Increased carboxyhemoglobin (HbCO₂)

_______ hormone is an anterior pituitary tropic peptide hormone that stimulates ovulation and the formation of the corpus luteum, along with FSH in females, and in males it stimulates the interstitial cells of the testes to synthesize testosterone.

Lutenizing Hormone; LH

The pathway to the blood takes excess fluid through ____ nodes, which are well prepared to elicit an immune response if necessary.

Lymph Nodes: - the lymphatic system is an integral part of the immune system, and a secondary fluid circulation system.

Throughout the lymphatic system are many ______ containing large quantities of _____.

Lymph nodes; lymphocytes

The ____ system collects excess interstitial fluid and returns it to the blood. Describe it:

Lymphatic System: - it is made up of a network of vessels that carry a clear fluid called lymph - lymph travels throughout this one-way open system always towards the heart - Lymphoid tissue is found in many organs, particularly the lymph nodes

What are the 3 basic aa?

Lysine, arginine, histidine

Which cycle is longer, lytic or lysogenic?

Lysogenic cycle is longer

______ contain acid hydrolases- hydrolytic enzymes that function best in an acid environment, such as proteases, lipases, nucleases, and glycosidases.

Lysosomes; together, these enzymes are capable of breaking down every major macromolecule within the cell. Lysosomes fuse with endocytotic vesicles and digest their contents. - Lysosomes will also take up and degrade cytosolic proteins in an endocytotic process.

What do agranular monocytes mature into?

Macrophages

What is lodged between the many myofibrils?

Mitochondria and many nuclei... Skeletal muscle is multi-nucleated

Since capillaries are found close to all cells in the body, they undergo a unique form of fluid exchange called?

Microcirculation: Microcirculation is the delivery of fresh blood to the smallest blood vessels, present in the vasculature embedded within organ tissues. - The vessels on the arterial side of the microcirculation are called the arterioles, which are well innervated, are surrounded by smooth muscle cells, and are 10-100 µm in diameter. Arterioles carry the blood to the capillaries, which are not innervated, have no smooth muscle, and are about 5-8 µm in diameter. Blood flows out of the capillaries into the venules, which have little smooth muscle and are 10-200 µm. The blood flows from venules into the veins. In addition to these blood vessels, the microcirculation also includes lymphatic capillaries and collecting ducts. The main functions of the microcirculation include the regulation of 1. blood flow and tissue perfusion 2. blood pressure, 3. tissue fluid (swelling or edema), 4. delivery of oxygen and other nutrients and removal of CO2 and other metabolic waste products, and 5. body temperature. The microcirculation also has an important role in inflammation. Most vessels of the microcirculation are lined by flattened cells, the endothelium and many are surrounded by contractile cells the smooth muscle or pericytes. The endothelium provides a smooth surface for the flow of blood and regulates the movement of water and dissolved materials in the plasma between the blood and the tissues. The endothelium also produce molecules that discourage the blood from clotting unless there is a leak. The smooth muscle cells can contract and decrease the size of the arterioles and thereby regulate blood flow and blood pressure.

Describe Microfilaments:

Microfilaments are smaller than microtubules. - the polymerized protein actin forms a major component of microfilaments. - Microfilaments produce the contractile force in muscle as well as being active in cytoplasmic streaming- responsible for amoeba-like movement, phagocytosis, and microvilli movement.

_____ arise from white blood cells called monocytes. They phagocytize microbes and cellular debris in the CNS.

Microglia: -

Describe microtubule growth:

Microtubule polymerization stars at the MTOC, where 13 gamma tubulin molecules are first added in a circular shape. - Growth of the microtubule occurs with the addition of alternating alpha/beta tubulin dimers, each bound to GTP (tubulin is an alpha/beta heterodimer) - The GTP is quickly hydrolyzed, but a GTP tubulin cap at the + end of the growing microtubule prevents spontaneous depolymerization. - When the microtubule is to be depolymerized, hydrolysis of GTP catches up to the + end, and the entire structure collapses.. called catastrophe.

The mitotic spindle, flagella and cilia are all made from _____.

Microtubules

Describe Microtubules:

Microtubules are larger than microfilaments. Microtubules are rigid, hollow tubes made from tubulin. Although tubulin is a globular protein, under certain cellular conditions it polymerizes into long straight filaments. - thirteen of these filaments lie alongside each other to form the hollow tube. The spiral appearance of the tube is due to the two types of tubulin, alpha and beta, used in the synthesis. - The tubules is made of alternating alpha-, beta- tubulin subunits - each of the 13 filaments, individually are referred to as protofilaments. - also play role in intracellular transport of organelles and vesicles with proteins like dynein and kynesin.

________ have a + and _ end.

Microtubules; - The - end attaches to a microtubule-organizing center (MTOC) in the cell. A microtubule grows away from the MTOC at its + end.

_____ ____ affect the electrolyte balance in the blood stream.

Mineral Corticoids

Dissolved inorganic ions inside and outside the cell?

Minerals.

Since slow twitch muscle fibres account for most of the workload in an endurance event, what organelle is most likely more abundant in slow twitch muscle fibres than in fast twitch?

Mitochondria

Which organelle in mammals plays an important role in apoptosis?

Mitochondria

Lodged between myofibrils are ____ and many ____.

Mitochondria and many nuclei, skeletal muscle is multinucleated

_____ increases the rate at which an axon can transmit signals.

Myelin: - The main purpose of a myelin layer (or sheath) is to increase the speed at which impulses propagate along the myelinated fiber. Along unmyelinated fibers, impulses move continuously as waves, but, in myelinated fibers, they hop or "propagate by saltation." Myelin decreases capacitance across the cell membrane, and increases electrical resistance. Thus, myelination helps prevent the electrical current from leaving the axon. - When a peripheral fiber is severed, the myelin sheath provides a track along which regrowth can occur. Unfortunately, the myelin layer does not ensure a perfect regeneration of the nerve fiber. Some regenerated nerve fibers do not find the correct muscle fibers and some damaged motor neurons of the peripheral nervous system (PNS) die without re-growth. Damage to the myelin sheath and nerve fiber is often associated with increased functional insufficiency. Unmyelinated fibers and myelinated axons of the mammalian central nervous system do not regenerate.

Myelinated axons appear ____ in color, while neuronal cells bodies appear ____.

Myelinated axons appear white in color, while neuronal cells bodies appear gray. Hence the name white matter and gray matter.

Several _____ are wrapped by a sarcolemma (plasma membrane) to form a muscle cell/muscle fiber.

Myofibrils

Why does muscle have a striated appearance?

Myofibrils are positioned end to end to form the myofibril, giving it the striated appearance.

How many ATPs are produced from each NADH and FADH₂ in the ETC?

NADH = 3 FADH₂ = 2

Fermentation recycles _____ back to ____?

NADH back to NAD+

What are the Agranular Lymphocytes?

NK cells, B-Lymphocytes, T-Lymphocytes + the monocytes

NTs and local mediators are often referred to as ____ ____; while ____ ___ are the hormones released by the endocrine system.

NTs and local mediators are often referred to as local hormones; while general hormones are the hormones released by the endocrine system.

What phylum do mammals belong to?

Phylum: Chrodata

What do plants form from glucose?

Plants form starch and cellulose from glucose.

What are the cell types that are derived from B-lymphocytes?

Plasma and memory cells

Describe what plasma is:

Plasma contains the matrix of blood, which includes water, ions, urea, ammonia, proteins, and other organic and inorganic compounds.

A _____ is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA.[1] They are double-stranded and, in many cases, circular.

Plasmid, they are not essential to the bacterium that carries them, and not all bacteria with plasmids can conjugate.

Which step is irreversible and commits the glucose molecule to the glycolytic pathway?

Step 3 via PFK-1 creating the fructose-1,6-biphosphate.

Describe the mechanism of steroid hormones:

Steroid hormones are derived from and are often chemically similar to cholesterol. - They are derived from cholesterol in the Smooth ER and mitochondria - As lipids, they are insoluble in water (hydrophobic), and they require proteins for transport through the blood stream. - When the steroid hormones arrive at an effector cell, they cross the cell membrane and bind to a receptor in the cytosol. - The cytosolic receptor + steroid complex move into the nucleus and influence gene expression by directly binding to the DNA and affecting gene transcription.

How do steroid hormones enter the cell and why?

Steroid hormones are lipid soluble thus they are able to diffuse directly through the hydrophobic cell membrane into the cytoplasm/cytosol.

Why do steroid hormones require a transport protein to dissolve into the blood stream?

Steroid hormones are lipids and thus water insoluble, and because of this they would coagulate in the blood stream. To prevent this, there are protein transport molecules that dissolve the steroid molecules in the blood. - There is usually a fraction of the steroid hormone in freeform in the blood while the rest is bound to the transport protein.

What is a main difference between the steroid hormones and the tyrosine hormones?

Steroid hormones diffuse through the cell membrane and bind with receptor in cytosol, whereas the tyrosine hormones diffuse directly into nucleus and bind to receptors there.

What are the need to know Steroid Hormones?

Steroid hormones: 1. The Glucocorticoids and mineral corticoids of the Adrenal Cortex: cortisol and aldosterone 2. The gonadal hormones: estrogen, progesterone, testosterone - Estrogen and progesterone are also produced by the placenta

What is the blastocyst made up of?

The blastocyst is made up of embryonic stem cells that each have the ability to develop into most of the types of cells in the human body.

Which pair of chromosomes in humans are the sex chromosomes?

The 23rd pair of chromosomes are the sex chromosomes. - In males, the pair appears as an X and a Y. - All other chromosomes appear as a pair of X's.

Explain how the AP propagates along the membrane of a neuron:

The AP occurs at a single point on a membrane and propagates along that membrane by depolarizing the section of membrane immediately adjacent to it. - The entire action potential as measured at one point on the membrane of a neuron takes place in a fraction of a millisecond.

Describe the Action Potential of Cardiac muscle:

The AP of cardiac muscle exhibits a plateau after depolarization. The plateau is created by slow voltage-gated calcium channels which allow calcium to enter and hold the inside of the membrane at a positive potential difference. -- the plateau lengthens the time of contraction

The ____ _____ is a disturbance in the electric field across the membrane of a neuron.

The Action Potential

What happens if a B lymphocyte is able to match its antibody with the antigenic determinant on a macrophage?

The B lymphocyte, with help from the Helper T cells, differentiates into plasma cells and memory B cells. - the plasma cells then begin to synthesize free antibodies and release them into the blood.

What is the shift due to pH called?

The Bohr shift

Where is the Bundle of His located?

The Bundle of His is located in the wall separating the ventricles.

What connects the CNS to the peripheral parts of the body?

The CNS is connected to the peripheral parts of the body by the Peripheral Nervous System.

How are the Ca²⁺ ions removed from the cytosol after muscle contraction?

The Ca²⁺ ions are removed from the cytosol by extremely efficient calcium pumps via active transport. - requires ATP - the mechanism involves an integral protein of the sarcoplasmic reticulum - it occurs against the concentration gradient - it is rapid and efficient

What happens to the Ca²⁺ ions at the end of each contraction cycle?

The Ca²⁺ is actively pumped back into the sarcoplasmic reticulum.

What connects the hypothalamus to the anterior pituitary gland?

The blood stream connects the hypothalamus to the anterior pituitary via the Hypothalamic-hypophyseal portal system.

Hooke's Law:

The amount of stretch or compression of an elastic material is directly proportional to the applied force. F=-k∆x The (-)ve sign indicates that the force is in the opposite direction of the displacement

What happens once antibodies bind to specific antigens?

The antibodies then start a cascade of reactions involving blood proteins, called complement, that cause the cell bearing the antigen to become perforated - the antibodies may also mark the antigen for phagocytosis by macrophages and NK cells - the antibodies may cause the antigenic substances to agglutinate or even precipitate, or, in the case of a toxin, the antibodies may block its chemically active portion.

In which part of the human body is the highest blood pressure found?

The aorta

What is the structure of phospholipids?

The are built from a glycerol backbone but a polar phosphate group replaces one of the fatty acids, therefore there are 2 fatty acid chains, glycerol backbone and a polar head group containing a phosphate group and a choline group. The phosphate group lies on the opposite side of the glycerol from the fatty acids, making the phospholipid polar at the phosphate end and nonpolar at the fatty acid end.

The ascending loop of Henle has very ____ permeability to water and ___ permeability to salt.

The ascending loop of Henle has very low permeability to water and high permeability to salt. - As filtrate rises out out of the medulla, salt diffuses out of the ascending loop of Henle, passively at first then actively. Therefore, water cannot enter or leave the loop, while sodium leaves. - The loop of Henle succeeds in moving a lot of sodium into the medulla of the kidney - the high osmotic pressure of the medulla is built up during the descending loop thus during the ascending loop more sodium is pulled out of the filtrate and into the medulla.

What controls the rate of the heart contractions?

The autonomic NS controls these contractions, nut the ANS does NOT initiate these contractions.

What part of the neuron generates the outgoing action potential?

The axon hillock: - a specialized part of the cell body (or soma) of a neuron that connects to the axon. As a result, the axon hillock is the last site in the soma where membrane potentials propagated from synaptic inputs are summated before being transmitted to the axon. For many years, it had been believed that the axon hillock was the usual site of action potential initiation. It is now thought that the earliest site of action potential initiation is found just adjacent, in the initial (unmyelinated) segment of the axon.[1] However, the positive point, at which the action potential starts, varies between cells. It can also be altered by hormonal stimulation of the neuron, or by second messenger effects of neurotransmitters. The axon hillock also functions as a tight junction, since it acts as a barrier for lateral diffusion of transmembrane proteins, GPI anchored proteins such as thy1, and lipids embedded in the plasma membrane.

What part of the neuron receives the signal from other axons?

The dendrite

What is the dermis?

The dermis is connective tissue derived from the mesodermal cells. The dermis is embedded by blood vessels, nerves, glands and hair follicles. - Collagen and elastic fibres in the dermis provide skin with strength, extensibility, and elasticity.

The descending loop has ____ permeability to salt and ___ permeability to water

The descending loop of Henle has Low permeability to salt and High permeability to water. So the osmolarity of the filtrate increases as water is removed.

The descending loop of Henle is ______ to water, while the ascending loop is _____ to water.

The descending loop of Henle is permeable to water, while the ascending loop is impermeable to water, and actively transport sodium into kidney

What type of muscle is the diaphragm and which nerve innervates it?

The diaphragm is skeletal muscle and it is innervated by the phrenic nerve.

What happens once the dipeptides and tripeptides enter the enterocytes (cells of the villi/brush border)?

The dipeptides and tripeptides are reduced to amino acids by the enzymes within the enterocytes.

What is the direction of the force given by the universal law of gravitation?

The direction is from the centre of mass of one object to the centre of mass of the other. According to Newton's third law, both masses experience a force of equal magnitude. Since this is true, the Earth pulls you toward its centre with a force equal to your weight, and you, in turn pull the Earth toward your centre with a force equal to your weight.

Where does the distal tubule empty into?

The distal tubule empties into The collecting duct

In which system does the distal convoluted tubule and the JGA play an important role and how does it do this?

The distal tubule plays an important role in the Renin-Angiotensin System to regulate blood volume/pressure and concentration. - The JGA connects the afferent arterioles of the glomerulus with the distal convoluted tubule. - The JGA senses changes in blood solute levels, thus during times of low sodium levels in the blood, specialized juxtaglomerular cells called granular cells secrete renin, which eventually leads to the release of aldosterone. - Aldosterone then acts on the distal tubule and collecting ducts to increase sodium reabsorption from the filtrate into the blood, thereby increasing blood osmolarity, volume and pressure.

What occurs in the distal convoluted tubule?

The distal tubule reabsorbs Na⁺ and Ca²⁺ while secreting K⁺, H⁺, and HCO⁻₃ back into the filtrate.

What is the major distinction between the methods of intercellular communication?

The distance travelled by the mediator: NTs travel over very short intercellular gaps/synapses Local mediators function in the immediate area around the cell from which they were released. Hormones travel throughout the organism via the blood stream

Where does the external auditory canal carry the sound to?

The external auditory canal carries the sound wave to the tympanic membrane or eardrum of the middle ear.

Once lipase has produced the fatty acids and monoglycerides from the triglycerides, where do they travel and what happens to them?

The fatty acid and monoglycerides products of lipase are shuttled to the brush border in bile micelles, and then absorbed by the enterocytes.

Where does the collecting duct carry the filtrate?

The filtrate is carried through the collecting duct of the nephron, through the highly osmotic medulla. - Many collecting ducts line up side by side in the medulla to make the Renal Pyramids - The collecting ducts lead to a Renal Calyx, which empties into the renal pelvis.

What happens to the filtrates osmolarity as it reaches the end of the descending loop?

The filtrates osmolarity increases from 300 to around 1200 once it reaches the end of the descending loop, because so much water has been pulled into the medulla.

What does the firing of one or more of the synapses onto an adjacent post synaptic membrane change?

The firing of one or more synapses onto a cell creates a change in the neuron cell potential. - This change in the cell potential is called either the Excitatory Postsynaptic Potential (EPSP) or the Inhibitory Postsynaptic Potential (IPSP)

What is the definition of the "fittest" organism in the theory or survival of the fittest?

The fittest organism is the organism which can best survive to reproduce offspring which will, in turn reproduce offspring and so on generation after generation. This definition may include living beyond reproduction in order to provide a better chance for offspring to reproduce.

What does the force of a contracting muscle depend on?

The force of a contracting muscle depends on number and size of the active motor units, and the frequency of action potentials in each neuron of the motor unit.

What is the periosteum?

The periosteum is a fibrous sheath that surrounds the long bones in the body. It is the site of muscle tissue attachment. - Periosteum is a membrane that lines the outer surface of all bones,[1] except at the joints of long bones.[2] Endosteum lines the inner surface of all bones. Periosteum consists of dense irregular connective tissue. Periosteum is divided into an outer "fibrous layer" and inner "cambium layer" (or "osteogenic layer"). The fibrous layer contains fibroblasts, while the cambium layer contains progenitor cells that develop into osteoblasts. These osteoblasts are responsible for increasing the width of a long bone[3] and the overall size of the other bone types. After a bone fracture the progenitor cells develop into osteoblasts and chondroblasts, which are essential to the healing process. As opposed to osseous tissue, periosteum has nociceptive nerve endings, making it very sensitive to manipulation. It also provides nourishment by providing the blood supply. Periosteum is attached to bone by strong collagenous fibers called Sharpey's fibres, which extend to the outer circumferential and interstitial lamellae. It also provides an attachment for muscles and tendons. Periosteum that covers the outer surface of the bones of the skull is known as "pericranium" except when in reference to the layers of the scalp

What role does the pharynx play?

The pharynx or throat functions as a passageway for food and air

Why does the membrane of the Eukaryotic cell invaginate?

The phospholipid bilayer of euks invaginates and separates to form individual, membrane bound compartments and organelles.

Describe how a photon hyperpolarizes the membrane of the rod cell?

The photon isomerizes retinal causing the membrane of the rod cell to become less permeable to sodium ions and hyperpolarize. the hyperpolarization is transduced into a neural action potential and the signal is sent to the brain.

What forms the placenta and what does the placenta do?

The placenta is formed from the tissue of the egg and the mother, and it takes over the job of hormone secretion. The placenta reaches full development by the end of the first trimester, and begins secreting its own estrogen and progesterone while lowering its secretion of HCG.

How is the plasmid transferred from the F+ bacterium to the F- bacterium?

The plasmid replicates differently than the circular chromosome. - One strand of the DS plasmid is nicked, and one end of this strand begins to separate from its complement as its replacement is replicated. The loose strand is then replicated and fed through the pilus to the other cell - Both cells then synthesize a complementary strand to reproduce the double stranded circular plasmid while at the same time, reproducing new pili as both cells are now viable donors

Why is the posterior pituitary also called the neurohypophysis?

The post pit is also called the neurohypophysis because it is composed mainly of support tissue for nerve endings extending from the hypothalamus.

Describe the post-synaptic membrane and what happens when NTs are released into the synaptic cleft:

The post synaptic membrane contains NT receptor proteins - Once the NTs attach to the receptor proteins, the postsynaptic membrane becomes more permeable to ions. - Ions move across the post-synaptic membrane through proteins called ionophores, completing the transfer of the neural impulse. - In this way, the impulse is not attenuated by electrical resistance as it move from one cell to the next.

What are the posterior pituitary hormones and where are they synthesized?

The posterior pituitary hormones are peptide hormones; ADH (Antidiuretic hormone) and Oxytocin. They are both synthesized in the hypothalamus, and then transported down nerve axons to the posterior pituitary where they are released in the blood.

Describe how the Voltage Gated Potassium Channels contribute to Repolarization:

The potassium channels are less sensitive to voltage change so they take longer to open. - By the time they begin to open, most of the sodium channels are closing. - Now K⁺ ions flow out of the cell making the inside more negative in a process called repolarization.

Describe how the Voltage Gated Potassium Channels contribute to hyperpolarization:

The potassium channels are slow to close as well so that, for a fraction of a second, the inside membrane becomes even more negative than resting potential - This portion of the process is called hyperpolarization.

Describe the Pre-Synaptic membrane and what happens when an AP arrives at the synapse:

The pre-synaptic membrane contains an unusually large number of Ca²⁺ voltage gated channels. - When an AP arrives at the pre-synaptic cleft, these channels are activated allowing Ca²⁺ to flow into the cell. - This sudden influx of calcium ions causes the release of the NT from their vesicles via an exocytotic process through the presynaptic membrane into the synapse. - The NT diffuses across the synaptic cleft via Brownian motion ( random motion of molecules)

What is the primitive streak in mammals?

The primitive streak is a structure that forms during the early stages of avian, reptilian and mammalian embryonic development, during early gastrulation. The presence of the primitive streak will establish bilateral symmetry, determine the site of gastrulation and initiate germ layer formation. To form the streak, reptiles, birds and mammals arrange mesenchymal cells along the prospective midline, establishing the first embryonic axis, as well as the place where cells will ingress and migrate during the process of gastrulation and germ layer formation. The primitive streak extends through this midline and creates the antero-posterior body axis, becoming the first symmetry-breaking event in the embryo, and marks the beginning of gastrulation. This process involves the ingression of mesoderm and endoderm progenitors and their migration to their ultimate position, where they will differentiate into the three germ layers (endoderm, mesoderm, ectoderm) that will give rise to all the tissues of the adult organism.

What do the proteoglycans of the ECM do?

The proteoglycans contain hydrated protein and carbohydrate chains, and can be very large. They typically create a gelatinous structure between the cells.

What happens to Hb's capacity to hold CO₂ when it is saturated with oxygen?

When Hb is saturated with oxygen, its capacity to hold carbon dioxide is reduced. The Haldane Effect

When does fermentation take place?

When a cell or organism is either unable to assimilate the energy from NADH and pyruvate, or has no oxygen available to do so.

When is a ratio of 1:1:1:1 observed in a dihybrid test cross?

When a heterozygous F2 progeny is test crossed with a homozygous recessive individual.

Describe Ketosis:

When glycogen stores are not available in the cells, fat (triacylglycerol) is cleaved to provide 3 fatty acid chains and 1 glycerol molecule in a process known as lipolysis. Most of the body is able to use fatty acids as an alternative source of energy in a process called beta-oxidation. One of the products of beta-oxidation is acetyl-CoA, which can be further used in the Krebs cycle. During prolonged fasting or starvation, acetyl-CoA in the liver is used to produce ketone bodies instead, leading to a state of ketosis. During starvation or a long physical training session, the body starts using fatty acids instead of glucose. The brain cannot use long-chain fatty acids for energy because they are completely albumin-bound and cannot cross the blood-brain barrier. Not all medium-chain fatty acids are bound to albumin. The unbound medium-chain fatty acids are soluble in the blood and can cross the blood-brain barrier.[3] The ketone bodies produced in the liver can also cross the blood-brain barrier. In the brain, these ketone bodies are then incorporated into acetyl-CoA and used in the citric acid cycle. The ketone body acetoacetate will slowly decarboxylate into acetone, a volatile compound that is both metabolized as an energy source and lost in the breath and urine. - Ketone bodies are acidic, but acid-base homeostasis in the blood is normally maintained through bicarbonate buffering, respiratory compensation to vary the amount of CO2 in the bloodstream, hydrogen ion absorption by tissue proteins and bone, and renal compensation through increased excretion of dihydrogen phosphate and ammonium ions.[4] Prolonged excess of ketone bodies can overwhelm normal compensatory mechanisms, leading to acidosis if blood pH falls below 7.35.

What do glial cells do when there is traumatic injury to the brain?

When injury to the brain, glial cells will multiply to fill any space created in the CNS, thus they are capable of cellular division.

Describe the changes in diaphragm shape as a person breathes.

When relaxed, the diaphragm is dome-shaped. It flattens upon contraction, expanding the chest cavity and creating negative gauge pressure, allowing for the lungs to take in air. - Thus, with negative gauge pressure, atmospheric pressure forces air into the lungs - Upon relaxation of the diaphragm, the chest cavity shrinks, aided by other intercostal muscles and abdominal muscles, and the elasticity of the lungs along with increased pressure in the chest cavity forces the air out of the body

What is the consequence when changes in spike proteins occur?

When spike proteins change, the antibodies can no longer recognize them, and the virus may avoid detection until new antibodies are formed.

When is an individual referred to as a hybrid?

When that individual has one dominant allele and one recessive allele of the same gene.

A single synapse usually releases how many types of NTs?

a single type, and is designed either to inhibit or excite, but not both. In other words, a single synapse releases only a single type of NT and it either excites or inhibits the next neuron, but does not do both. - A single synapse cannot change from inhibitory to excitatory, or vice versa.

What do prokaryotes possess instead of a nucleus?

a single, circular double stranded molecule of DNA. It is twisted into supercoils and is associated with histones in Archaea and with proteins that are different from histone in bacteria.

Who can an individual with Type O blood donate to?

anyone; they are the universal donor

Cytochromes:

are proteins which require a prosthetic heme group (nonprotein blood) in order to function. - Examples of cytochromes are hemoglobin and the cytochromes of the ETC in the inner membrane of the mitochondria.

What does it mean that a phospholipid is amphipathic?

having both polar and non-polar regions

What do the adhesive proteins provide for the ECM?

help individual cells within a tissue stick together.

Why is some urea passively transported back into the medulla from the collecting ducts?

helps to maintain the osmolarity of the interstitial space. - thus only occurs in the presence of ADH

It is the cooperativity in the presence of the allosteric inhibitor 2,3BPG that gives the oxygen dissociation curve of __________ its sigmoidal shape.

hemoglobin.

Autocrine:

term for hormones that act on same cells that secrete them

What level of protein structure does proline assist in creating?

tertiary.. the bends and folds

What does it mean than an AP is all or nothing?

the membrane completely depolarizes or no action potential is generated

Endocrine:

the secretion of an endocrine gland that is transmitted by the blood to the tissue on which it has a specific effect

What is the purpose for the delayed contraction of the AV Node?

to allow the atria and ventricles to fill with blood. They are slow to contract to allow for atrial emptying and ventricular filling. Basically, this delay allows the atria to finish their contraction, and to squeeze their contents into the ventricles before the ventricles begin to contract.

What is the net effect of GLucagon?

to raise blood glucose levels.

What is the function of triacylglycerols in the cell?

to store energy and potentially to provide thermal insulation and padding to an organism.