A&P Exam 1
Why are these molecules able to dissolve in fat? (hint - fat is a polar molecule)
"like dissolves like." This means that molecules with many polar groups are more soluble in polar solvents, and molecules with few or no polar groups (i.e., nonpolar molecules) are more soluble in non-polar solvents.
Is it active or passive?
***Active transport (sometimes called active uptake) is an energy-requiring process that moves material across a cell membrane. The cell uses active transport in three situations: when a particle is going from low to high concentration, when particles need help entering the membrane because they are selectively impermeable, and when very large particles enter and exit the cell. Passive transport means moving biochemicals and other atomic or molecular substances across membranes. Unlike active transport, this process does not involve chemical energy. Passive transport is dependent on the permeability of the cell membrane, which, in turn, is dependent on the organization and characteristics of the membrane lipids and proteins. The four main kinds of passive transport are diffusion, facilitated diffusion, filtration and osmosis.
Intracellular fluid?
- About 28 of the 42 liters of fluid in the body are inside the 100 trillion cells and are collectively called the intracellular fluid. Thus, the intracellular fluid constitutes about 40 percent of the total body weight in an "average" person. -The fluid of each cell contains its individual mixture of different constituents, but the concentrations of these substances are similar from one cell to another. In fact, the composition of cell fluids is remarkably similar even in different animals, ranging from the most primitive microorganisms to humans. For this reason, the intracellular fluid of all the different cells together is considered to be one large fluid compartment. Intracellular contains 2/3. Extracellular contain 1/3.
How are these vitamins absorbed?
- Food containing fat-soluble vitamins is ingested. - The food is digested by stomach acid and then travels to the small intestine, where it is digested further. Bile is needed for the absorption of fat-soluble vitamins. This substance, which is produced in the liver, flows into the small intestine, where it breaks down fats. Nutrients are then absorbed through the wall of the small intestine. - Upon absorption, the fat-soluble vitamins enter the lymph vessels before making their way into the bloodstream. In most cases, fat-soluble vitamins must be coupled with a protein in order to travel through the body. - These vitamins are used throughout the body, but excesses are stored in the liver and fat tissues. - As additional amounts of these vitamins are needed, your body taps into the reserves, releasing them into the bloodstream from the liver.
What are the two water compartments in the body?
-The total body fluid is distributed mainly between two compartments: the extracellular fluid and the intracellular fluid.
How is it related to a H+?
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How is this important to 'life'?
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Label the polar parts.
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Why is the range so narrow?
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What is the range of pH in body fluids?
0 to 14. The closer the number is to 0 the more acidic the substance is, and the higher the number, the more basic the compound.
List the ions found in the cytoplasm.
02, K+, Na+, Cl-.
What are the factors that affect Basal Metabolic Rate (BMR) ?
1. Amount of lean body mass: muscle, liver, brain, kidney all metabolize at a high rate at rest, and have high energy needs when more active. 2. Gender: males average a higher BMR because of a greater proportion of lean body mass. 3. Body temperature: fever, for example, increases BMR. 4. Thyroid hormone: higher amounts increase metabolic rate—but too much or too little of the hormone can cause significant health problems. 5. Age: metabolic rate declines with age. 6. Nutritional state: eating less, as in dieting, slows metabolic rate, at least in the short term. 7. Pregnancy/breast feeding: these increase metabolic rate—but not so much that you need to resort to "eating for two." 8. Rapid growth and/or development—infancy, growth spurts, healing after illness or injury. 9. Caffeine and tobacco use: can increase metabolic activity. 10. Heredity: hereditary factors, some of which are implicated in the previous points, can influence basal metabolism. We all know of people who seem to eat like horses but who never seem to gain weight, and others who eating normal amounts gain weight easily. Some people have what can be called a thrifty metabolism—that is, they conserve more energy than the average person, so it is much easier for them to gain weight. This type of metabolism is an advantage when food is in short supply, or when there is famine, but in Western cultures, this is rarely the case. Have you inherited a thrifty metabolism? A child with no obese parents has only a 10% risk of becoming obese; a child with one obese parent has a 40% risk, and with two obese parents, 80%. (Culture, and family practices play a role here as well).
List the six types of proteins found in the cell membrane.
1. Transporters. 2. Enzymes. 3. Cell surface receptors 4. Cell surface identity markers. 5. Cell adhesion proteins. 6. Attachments to the cytoskeleton.
Remember the six proteins?
1. Transporters. 2. Enzymes. 3. Cell surface receptors 4. Cell surface identity markers. 5. Cell adhesion proteins. 6. Attachments to the cytoskeleton.
What are their functions?
1. Transporters. Membranes are very selective, allowing only certain substances to enter or leave the cell, either through channels or carriers. In some instances, they take up molecules already present in the cell in high concentration. 2. Enzymes. Cells carry out many chemical reactions on the interior surface of the plasma membrane, using enzymes attached to the membrane. 3. Cell surface receptors. Membranes are exquisitely sensitive to chemical messages, detecting them with receptor proteins on their surfaces that act as antennae. 4. Cell surface identity markers. Membranes carry cell surface markers that identify them to other cells. Most cell types carry their own ID tags, specific combinations of cell surface proteins characteristic of that cell type. 5. Cell adhesion proteins. Cells use specific proteins to glue themselves to one another. Some act like Velcro, while others form a more permanent bond. 6. Attachments to the cytoskeleton. Surface proteins that interact with other cells are often anchored to the cytoskeleton by linking proteins.
What is the normal pH of the body/blood?
7.0
What is the normal range of body temperature?
98.6 is the average.
Define a calorie.
A calorie is the amount of energy required to raise the temperature of one cubic centimeter of water one degree centigrade.
What is the form of energy used for metabolic processes?
A cell's daily operations are accomplished through the biochemical reactions that take place within the cell. Reactions are turned on and off or sped up and slowed down according to the cell's immediate needs and overall functions. At any given time, the numerous pathways involved in building up and breaking down cellular components must be monitored and balanced in a coordinated fashion. To achieve this goal, cells organize reactions into various enzyme-powered pathways.
How is the earth dipolar?
A dipole is a polar molecule. This is a molecule that has relatively constant partial positive and negative charges that are physically discrete, i.e. separated from one another.
Define a kilocalorie
A kcal (kilocalorie) is 1000 (cal) calories.
What is a macrophage?
A macrophage is a large cell in your body that is involved with the immune system. More specifically it is part of the innate or not specific immune system. Macro means large, and phage means "an eater." So it "eats" bacteria and viruses in your body.
What is a polar molecule?
A polar molecule has a positive and negative end because of electronegativity. H2O, for example, is a polar molecule because 1) it has lone pairs 2) the oxygen is pulling the electrons from the hydrogen into its vicinity making it have a slightly negative charge while the two hydrogen have a slightly positive charge.
What are the characteristics of polar molecules?
A polar molecule will have a mainly negative charge on one side, with a mainly positive charge on the other side. This allows other molecules to attach via opposite ends. It is this bond that allows the double helix form of a DNA molecule to exist.
What is the energy molecule of the body?
ATP
What is an enzyme?
An enzyme is a protein that acts as a catalyst for the chemical reactions.
Negative feedback mechanisms
Are DIRECTLY HOMEOSTATIC - they counteract the trend, returning the body toward homeostasis. If your body temperature is rising above normal: say it's 100 F and normal is 98.6 F, you start to sweat which COOLS the body. As the body cools, the temperature drops to 97 F and you start to shiver, which then WARMS the body. Your temperature rises to 99 and you stop shivering, and start sweating again and so on. In this manner the body maintains a temperature between 97.4 and 100.1 degrees F. The AVERAGE for most people is 98.6 F - and this is why we define homeostasis as the existence and maintenance of a RELATIVELY constant internal environment. 99% of the body's internal conditions are maintained by NEGATIVE feedback mechanisms because this mechanism is directly homeostatic
Positive feedback mechanisms
Are NOT directly homeostatic - they reinforce the trend, pushing the body farther away from homeostasis. Uterine contractions during childbirth start mild and far apart. As labor progresses, the contractions get stronger and closer together. Eventually, the contractions are strong enough and frequent enough to cause delivery of the baby - and the body, having expelled the baby, returns to normal homeostasis. Blood pressure drop during hemorrhage is also a positive feedback mechanism - however this is LETHAL.
Why does "life' need a 'liquid'?
Because it's necessary for all life on earth, it has certain unusual properties. Water is a universal solvent that is essential to all life that we know of. It is thought other solvents like liquid methane might be able to support life but that hasn't been demonstrated - however we do know for a fact that water is what is essential for all life on Earth that we know of.
Draw a polar molecule.
Bent, Pyramidal, and always asymmetrical. Hydrogen Sulfide (H2S).
KNOW this formula!
C6H12O6 + 6 O2 + H2O --> 6 CO2 + H2O + 38ATP
What electrical charge does an electron have?
Carry a negative charge -
What process produces this molecule?
Cellular respiration is the breakdown of glucose (sugar) molecules to release energy contained in the chemical bonds between the atoms that make up the glucose molecule. As the glucose molecule is broken apart, electrons are stripped from the molecule and passed from one electron carrier molecule to the next and ultimately to an Oxygen atom - remember oxygen WANTS 2 electrons very badly. Carbon dioxide is the waste product of the glucose molecule and contains no useable energy for living organisms.
Define polar?
Chemical bonding is the result of either an atom sharing one or more outer orbit electrons with another atom or an atom taking outer orbit electrons from the atom with which it is bonding.
What are the constituents of the cytoplasm?
Cytosol (fluid portion) - contains dissolved solutes; organelles - ribosomes (sites of protein synthesis), rough endoplasmic reticulum ( makes proteins that are secreted from the cell & makes the cell's membrane), smooth endoplasmic reticulum ( site of lipid and steroid synthesis, lipid metabolism, and drug detoxification), Golgi apparatus ( packages, modifies, and segregates proteins for secretion from the cell), lysosomes ( sites of intracellular digestion / the cells garbage can so to speak), mitochondria( powerhouse of the cell/ site of ATP synthesis), peroxisomes ( detoxify many toxic substances- breaks down hydrogen peroxide), centrioles, microtubules, microfilaments, intermediate filaments.
List the macromolecules found in the cytoplasm.
Cytosol contains all of them with many proteins and nucleic acids. Proteins make up all of the structural components and enzymes that are present and nucleic acids, specifically messenger RNA and transfer RNA and ribosomal RNA are quite abundant in the cytoplasm for the purpose of synthesizing more proteins. Lipids are present in the cytosol in the form of vesicles, but these are technically not really part of the cytoplasm. However, there are various fatty acid molecules that are present in the cytoplasm. Importantly, glucose (just like many other carbohydrates), the cell's typical source of energy is present in the cytoplasm, having been transported into the cell from the extracellular space.
Where does glycolysis occur?
Cytosol. Glycolysis takes place In the cytosol.The cytoplasm refers to the space between the cell membrane and the nucleus, including the intracellular fluid and organelles. The cytosol, however, refers to just the fluid. Although cytoplasm would probably be accepted as a valid answer, cytosol is the terminology you want to use.
What is the 'liquid' of the cytoplasm?
Cytosol: The cytosol is the portion of the cytoplasm not contained within membrane-bound organelles. Cytosol makes up about 70% of the cell volume and is composed of water, salts and organic molecules.
What electrical charge does a neutron have?
Do not carry a charge, they are neutral and have no charge.
What 'gives' enzymes their specific function?
Each specific type of enzyme is specific for one particular type of reaction - their shape determines their function - lose shape ( denature) lose function.
A peroxisome?
Enzyme containing structures that help to detoxify alcohol, form bile acid, and break down fats.
What is the function of enzymes?
Enzymes speed up metabolic reactions.
What does 'essential' mean in the terms 'essential fatty acid' and 'essential amino acid'?
Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them. The term "essential fatty acid" refers to fatty acids required for biological processes, and not those that only act as fuel. An essential amino acid may also be called an indispensable amino acid. This is an amino acid that the body cannot synthesize on its own, so it must be obtained from the diet. Because each has its own physiology, the list of essential amino acids is different for humans than it is for other organisms.
What is the molecular formula for water?
H2O
What electrical charge does a proton have?
Has a positive charge +
How is 'homeostasis related to enzyme function?
Homeostasis is the maintenance of a stable/constant internal environment with normal set limits regardless of external change/activity. One factor to consider is temperature. Our body temperature is kept regulated at 37.5 degrees and enzymes in our body have an optimum temperature of 40 degree, meaning this is the temperature they 'work best' at. If our body temperature was to increase above 40 degrees, this high temperature will denature our enzymes, altering the shape of their active sites and therefore corresponding substrates will no longer fit in the enzyme's active site and form the enzyme-substrate complex i.e. the enzyme's active site is no longer complementary to the substrate, therefore metabolic reactions cannot occur. Homeostasis is therefore key to regulating our body temperature to ensure it does not increase above this optimum temperature.
Define hydrophilic.
Hydrophilic will dissolve in water or form hydrogen bonds with water molecules.
Define hydrophobic.
Hydrophobic molecule does not interact with water because it is non-polar.
What happens if the shape of the enzyme changes?
If the enzyme loses its shape it loses its ability to function as designed - it becomes denatured and not functional.
Water is found either inside or outside of what structure?
Intracellular Fluid (ICF) comprises 2/3 of the body's water. If your body has 60% water, ICF is about 40% of your weight. The ICF is primarily a solution of potassium and organic anions, proteins etc. (Cellular Soup!). The cell membranes and cellular metabolism control the constituents of this ICF. ICF is not homogeneous in your body. It represents a conglomeration of fluids from all the different cells. Extracellular Fluid (ECF) is the remaining 1/3 of your body's water. ECF is about 20% of your weight. The ECF is primarily a NaCl and NaHCO3 solution. The ECF is further subdivided into three subcompartments: Interstitial Fluid (ISF) surrounds the cells, but does not circulate. It comprises about 3/4 of the ECF. Plasma circulates as the extracellular component of blood. It makes up about 1/4 of the ECF. Transcellular fluid is a set of fluids that are outside of the normal compartments. These 1-2 liters of fluid make up the CSF, Digestive Juices, Mucus, etc. Intracellular Fluid (ICF) comprises 2/3 of the body's water.
Know the symbols for the major ions found in the body? FYI: Ions are atoms or molecules that have gained or lost one or more of their valence electrons and have a net positive or negative charge.
Ions in body Na+ Sodium K+ potassium Cl- chloride Ca+ calcium. There are anions denoted A- that are intracellular ( you can find some info on them in textbook but they aren't talked about that much.
What is lysozyme?
Is an enzyme occurring naturally in egg white, human tears, saliva, and other body fluids, capable of destroying the cell walls of certain bacteria and thereby acting as a mild antiseptic.
Define homeostasis.
Is the ability to maintain a constant internal environment in response to environmental changes. It is a unifying principle of biology.
What is homeostasis?
Is the maintenance of a relatively stable internal environment - it's necessary for survival and function of all cells- it's maintained via self- regulating mechanisms. Homeostasis is maintained by feedback mechanisms: negative or positive.
What is its function?
It speeds up the reaction. They work to make reactions go faster in digestive and metabolic (energy related) processes. They are called 'catalysts' because they speed up the reaction by lowering the amount of energy needed to get the reaction started.
Where does Krebs cycle occur?
Kreb's cycle normally occurs in the matrix of the mitochondria. This cycle is also referred to as citric acid cycle or Tricarboxylic acid and it normally involves the breaking down of food molecules into carbon dioxide, water as well as energy.
How do polar molecules pass through the cell membrane?
Large polar molecules and ions that cannot pass through phospholipid bilayer. (Facilitated diffusion) Channel proteins - Create a 'channel' that specific ions can flow through Carrier proteins - Physically bind to the substance on one side of membrane and release it on the other.
What is the function of water in metabolism?
Metabolic reactions are all the chemical process's that occur in the cells. These chemicals will all be dissolved in water and also transported dissolved in water. No reactions will take place unless water is present and waste products of metabolism will also be excreted in solution to some extent. Different reactions obviously vary greatly but water is the medium in which they all take place
What is metabolism?
Metabolism is all of the chemical reactions that occur in a cell during growth and repair - it is the whole range of biochemical processes that occur within the body.
What is the powerhouse of the cell?
Mitochondria
Why is it called that?
Mitochondrion is called the power house of the cell because the most of the ATP of the cell is produced here and that is the only use able form of energy by humans.
What is a non-polar molecule?
Molecule which has no separation of charge, so no positive or negative poles are formed. Examples: O2, CO2, N2Tetrahedral, Linear, trigonal planar, depends on symmetry.
How are enzymes important to life?
Nearly all the biochemical reactions that occur in your body are non-spontaneous. This means they do not occur on their own, because they need energy to start. Kind of like you need a spark to start a fire; things generally don't just spontaneously ignite. Enzymes are biological catalysts: they lower the activation energy that is required for the reactions to proceed, so that metabolism can occur without too much energy input. Without enzymes, biochemical reactions would stop and you would die.
What are the characteristics of non-polar molecules?
Non-polar molecules are symmetrical about the center of the molecule. This is to balance the electronegativity of the molecule, as each charge around the central atom must balance in order for there to be no overall polarity to one side of the molecule.
What is the 'normal' blood pressure?
Normal BP 120/80 mm Hg Systolic is 120mm of Hg Diastolic is 80mm of Hg Above this range is hypertension Below this range is hypo tension
**NOTE***
O2 combines with H's to form H2O. Glucose is broken down into CO2 The energy from the glucose is transferred to ATP (40%) or lost as heat (60%).
What happens when you mix olive oil and vinegar? WHY?
Olive oil is less dense, it floats on top of the vinegar. Even if you mix them together, they will eventually seperate again. Olive oil is a hydrophobic (water-adverse) organic liquid. Vinegar is a 5% solution of acetic acid in water,. So vinegar(polar) is mostly water. Water and oil(non-polar) don't mix.
Draw and label a water molecule. Show its polarity
One Oxygen and two hydrogen.
What is Phagocytosis?
Phagocytosis (literally "cell-eating") is a form of endocytosis wherein large particles are enveloped by the cell membrane of a (usually larger) cell and internalized to form a phagosome, or "food vacuole." The cell engulfs a large particle by forming projecting pseudopods ("false feet") around it and enclosing it within a membrane sac called a phagosome. The phagosome is combined with a lysosome. Undigested contents remain in the vesicle (now called a residual body) or are ejected by exocytosis. Vesicle may or may not be proteincoated but has receptors capable of binding to microorganisms or solid particles.
What is the primary component of the cell membrane?
Phospholipid Bilayer - A collection of substances which are made up of phosphates and lipids. They create a partially permeable membrane, which allows only certain substances to diffuse through the membrane. Cholesterol - Mantains fluidity of cell surface membrane. Glycoproteins - Used in cell recognition, and they act as receptors and antigens. They are made of sugar chains. Proteins - Control what enters and leaves the cell. - Channel proteins allow polar substances or small substances pass through facilitated diffusion. - Carrier proteins, included in bulk transport, require ATP to move substances in or out the cell. Glycolipids - Attached to phospholipids, with sugar chains. ( same role as glycoproteins).
What is a phospholipid?
Phospholipids are lipids that in their simplest form is composed of glycerol bonded to two fatty acids and a phosphate group. The resulting compound called phosphatidic acid contains a region (the fatty acid component) that is fat-soluble along with a region (the charged phosphate group) that is water-soluble. Triglycerides are the chemical form in which most fat exists in food as well as in the body. They're also present in blood plasma and, in association with cholesterol, form the plasma lipids.
What are the characteristics of it's parts?
Phospholipids are similar to triglicerides, which are formed by combining glycerol with three fatty acids. However, a phosphate functional group is substituted for one of the three fatty acids, so the composition is different. The fatty acid tails of a phospholipid are non-polar, while the phosphate head is polar. This leads to a chemically confused molecule that's able to form a unique assembly known as a "bi-layer" when it's exposed to water. This bi-layer is what surrounds the cells.
Pinocytosis?
Pinocytosis ("cell-drinking") is a form of endocytosis, a process in which small particles are taken in by a cell by splitting into smaller particles. The particles then form small vesicles which subsequently fuse with lysosomes to hydrolyze, or to break down, the particles. This process requires adenosine triphosphate (ATP), the chemical compound used as energy in a majority of cells. Pinocytosis is primarily used for the absorption of extracellular fluids (ECF), and in contrast to phagocytosis, generates very small vesicles. Unlike receptor-mediated endocytosis, pinocytosis is unspecific in the substances that it transports. The cell takes in surrounding fluids, including all solutes present. The cell "gulps" a drop of extracellular fluid containing solutes into tiny vesicles. No receptors are used, so the process is nonspecific. Most vesicles are protein-coated.
What is a proton?
Positively charged particles in an atoms nucleus, gives an element its identity, has a mass amount of 1 amu.
List the four shapes of proteins.
Primary - a string or rope-like linear structure. Microfilaments and micro tubules. Secondary - folded, twisted primary proteins - with a 3-D shape either spiral or sheet like. The sheet looks like a piece of paper. Tertiary - a 'glob' of primary and secondary shapes all wadded up into a ball. The globulins of the antibodies in the immune system are examples. Quaternary - a blob of primary, secondary and tertiary shaped proteins attached to one another. The hemoglobin molecule is an example.
Why is 'shape' important to proteins?
Proteins cannot function properly unless they are folded into their correct shape- proteins are of primary importance to the structure and function of the cells - if they lose their shape they don't function correctly and therefore the body cannot function correctly - can lead to disease and to death
Living things concentrate solutes AGAINST the concentration gradient - HOW?
Random movement of the molecules will cause some to pass through the pores; this will happen more often on the side with more molecules. The molecules diffuse from where it is more concentrated to where it is less concentrated. This leads to a dynamic equilibrium: The solute molecules continue to cross the membrane, but at equal rates in both directions.
What does the word 'viscera' refer to?
Refers to the internal organs of the body - within the ventral body cavity ( includes stomach, heart, lungs, bladder, spleen,etc). The part that is attached to the surface of the organ itself.
Why is Rough ER called 'rough'?
Ribosomes make up the rough ER so it has a very rough texture. The rough ER also aids in protein synthesis.
What are the functions of each constituent?
Ribosomones - important for the processing of proteins, both within the cell intself and in other parts of the body Endoplasmic tericulum - a tubular system within the cell that tranports molecules. Golgi apparatus - located near the nucleus and responsible for distributing proteins the ribosomes processed. Mitochondria - prinicipal source of cellular energy. contains the enzymes involoved with electron transport and the citric and fatty acid cycles Lysosomes - tiny membranous sacs that contain enzymes used to break down protein, carbohydrates, acids, and foreign substances that may enter the cell. Peroxsomes - found most commonly in cells of the liver and kidneys. mainly serve to break down toxic substances. Centrosomes - vital for cellular reproduction. distribute chromosomes, which carry deoxyribonucleic acid (DNA) information to newly forming cells. Cilia and flagella - tiny projections that extend outward from cell surfaces. Responsible for cell movement and the movement of cell products. Vesicles - membranous sacs that vary in size. are actually an extension of the cell membrane that folds inqard into the cytoplasm Microfilaments - are responsible for cell contraction. Microtubules - ser as an internal cell "skeleton" that helps maintain the shape of a cell .
What is a lysosome?
Sacs of enzymes that digest cellular macromolecules such as nucleic acids.
The cell is the basic unit of all living things?
Since the cell is the building block of all living things - knowledge of the cells parts and how the function of each is essential to understanding how the larger structure functions.
Define solid, liquid, and gas.
Solid - atoms are very compact; with definite shape, volume and mass. Liquid - atoms are not too compact; with a definite volume, mass but with no definite shape. Gas - atoms are far away from each other; without a definite volume, mass, and shape.
How is stress related to Homeostasis?
Stress and homeostasis are at odds with one another within the body of a living organism. An organism is designed to be in a state of homeostasis, where all the systems within its body are functioning optimally. Stress pushes the organism out of homeostasis, forcing it to compensate for changes in the environment or within its internal systems. In biology, stress may refer to physical and environmental challenges as well as emotional and psychological ones that can have an effect on an organism's body. Organisms are never fully free from stress and are thus never in a true state of homeostasis, though they are usually in a state that is relatively stable.
Give some examples of stressors?
Stresses in the environment, such as those caused by temperature or the presence of danger, as well as those within the organism, such as those caused by hunger, thirst, or emotional discomfort will all cause the organism to move out of homeostasis as the stressor is dealt with. Most of the time, stress and homeostasis are in a balance that allows the organism to survive though not always to thrive. In this process, a stressor, such as the fear brought on by the presence of a predator, causes the body to release adrenaline so that it can escape from danger and survive. The stressor causes the body to leave a state of homeostasis and to enter a state of "fight-or-flight," in which the heart beats faster, the respiration quickens, and unneeded systems, such as digestion and color vision are temporarily switched off. Once the threat is no longer present, the body will calm down and return to a state of homeostasis.
Where does the electron transport system occur?
The Electron Transport Chain: is made of electron carrier molecules embedded in the inner mitochondrial membrane. Each successive carrier in the chain has a higher electronegativity than the carrier before it, so the electrons are pulled down hill toward the oxygen. Except for ubiquinone (Q), most of the carriers are protein containing a non -protein cofactor. The cofactors alternate between an oxidized and reduced state as they accept and donate electrons. It is here that the majority of the ATP is produced.
What does the lipid 'tail' layer do?
The arrangement of hydrophilic("philic"=love) and hydrophobic("phobic"= fear) heads of the lipid bilayer prevents hydrophilic solutes from passively diffusing across the band of hydrophobic tail groups, allowing the cell to control the movement of these substances via transmembrane protein complexes such as pores and gates.
How are these molecules 'arranged'?
The carbohydrates The phospholipids The proteins
Name the two parts and the 'water' characteristic of each part.
The carbohydrates - are found on the outer surface of all eukaryotic cell membranes, and are attached to the membrane proteins or sometimes to the phospholipids. Proteins with carbohydrates attached are called glycoproteins, while phospholipids with carbohydrates attached are called glycolipids. The carbohydrates are short polysaccharides composed of a variety of different monosaccharides, and form a cell coat or glycocalyx outside the cell membrane. The glycocalyx is involved in protection and cell recognition, and antigens such as the ABO antigens on blood cells are usually cell-surface glycoproteins. The phospholipids - are arranged in a bilayer, with their polar, hydrophilic phosphate heads facing outwards, and their non-polar, hydrophobic fatty acid tails facing each other in the middle of the bilayer. This hydrophobic layer acts as a barrier to all but the smallest molecules, effectively isolating the two sides of the membrane. Different kinds of membranes can contain phospholipids with different fatty acids, affecting the strength and flexibility of the membrane, and animal cell membranes also contain cholesterol linking the fatty acids together and so stabilising and strengthening the membrane. The proteins - usually span from one side of the phospholipid bilayer to the other (integral proteins), but can also sit on one of the surfaces (peripheral proteins). They can slide around the membrane very quickly and collide with each other, but can never flip from one side to the other. The proteins have hydrophilic amino acids in contact with the water on the outside of membranes, and hydrophobic amino acids in contact with the fatty chains inside the membrane. Proteins comprise about 50% of the mass of membranes, and are responsible for most of the membrane's properties. - Proteins that span the membrane are usually involved in transporting substances across the membrane (more details below). - Proteins on the inside surface of cell membranes are often attached to the cytoskeleton and are involved in maintaining the cell's shape, or in cell motility. They may also be enzymes, catalysing reactions in the cytoplasm. - Proteins on the outside surface of cell membranes can act as receptors by having a specific binding site where hormones or other chemicals can bind. This binding then triggers other events in the cell. They may also be involved in cell signalling and cell recognition, or they may be enzymes, such as maltase in the small intestine (more in digestion).
What is extracellular fluid?
The extracellular fluid is divided into the interstitial fluid and the blood plasma. All the fluids outside the cells are collectively called the extracellular fluid. Together these fluids account for about 20 percent of the body weight, or about 14 liters in a normal 70-kilogram man. The two largest compartments of the extracellular fluid are the interstitial fluid, which makes up more than three fourths (11 liters) of the extracellular fluid, and the plasma, which makes up almost one fourth of the extracellular fluid, or about 3 liters. The plasma is the noncellular part of the blood; it exchanges substances continuously with the interstitial fluid through the pores of the capillary membranes. These pores are highly permeable to almost all solutes in the extracellular fluid except the proteins. Therefore, the extracellular fluids are constantly mixing, so the plasma and interstitial fluids have about the same composition except for proteins, which have a higher concentration in the plasma
What type substance can dissolve polar molecules?
The general rule is like dissolves like, so polar compounds will dissolve in water (which is polar) and non-polar compounds will dissolve in butane (non-polar). The water/butane are just examples - you can replace them with anything that is polar/non-polar, respectively.
Know the symbols for the major elements found in the body?
The major elements would be carbon C - hydrogen H - oxygen O - nitrogen N also phosphorus P and sulfur S- carbon, hydrogen, oxygen, and nitrogen the most prevalent - carbon is more than prevalent than the others.
How do nonpolar molecules pass through the cell membrane?
The phospholipids that make up the membrane are polar. Thus, they "repel" polar molecules, but they allow nonpolar molecules to pass through via (simple) diffusion. (Polar molecules, however, must use the transport proteins).
Describe the sodium/potassium pump. What is its function?
The sodium-potassium pump is a transmembrane protein that maintains Na+ and K+ ion concentrations outside and inside the cell, respectively, at elevated levels. It does this by pumping 3 Na+ ions out of the cell, and then 2 K+ ions into the cell, using 1 ATP to do so.
Which is on the nutrition label on foods?
The thing to note is that when dieticians and doctors talk about calories (and when we talk ablout calories in terms of daily intake i.e. 200-3500) they are referring to the kcal value on the food products.
Describe this in terms of polarity?
The true cause is the difference in the polarity of the water in the vinegar and the lipids in the oil. Water molecules have a positively and a negatively charged end. Molecules of this nature are called "polar" molecules, and easily bond with one another. Lipids, on the other hand, are non-polar; they have no separation of charge. This means it is much easier for water to bind with more water than for it to bond with oil, and nature much prefers the path of least resistance. In the end, the oil is less dense, which is why it floats to the top, but not why it won't combine.
List the water soluble vitamins.
There are a total of nine water-soluble vitamins: the B vitamins -- folate, thiamine, riboflavin, niacin, pantothenic acid, biotin, vitamin B6 and vitamin B12 -- and vitamin C.
What is the function of the nucleopores?
Tiny hole within the nuclear membrane that allows nucleic acids and proteins to move into and out of the nucleus.
Why is Smoothe ER called 'smooth'?
Unlike the rough ER, the smooth ER is not studded with ribosomes. This gives it a smooth appearance.
List the Fat soluble vitamins.
Vitamins: A, D, E, and K.
How is water involved in these chemical reactions?
Water is involved in breaking bonds ( hydrolysis ) and also involved in dehydration synthesis. Water can dissolve polar substances - hydrophobic is water fearing - hydrophilic is water loving. Hydrophobic molecule does not interact with water because it is nonpolar. Hydrophilic will dissolve in water or form hydrogen bonds with water molecules.
Why are these molecules water soluble?
Water-soluble vitamins are those that dissolve in water upon entering the body. Because of this, your body cannot store excess amounts of water-soluble vitamins for later use.
List some things that 'denature' enzymes.
When a protein loses its functional conformation, it is said to have Denatured. Functional conformation is the structure in which the protein is able to perform its functions at optimal inefficiencies. Heat, pH extremes, chemicals, electricity, radiation, and by other causes all denature protein, which means enzymes (proteins) become altered.
Name the two places water is found in the body.
Within our cells (two-thirds of the water), in the space between our cells and in our blood (one-third of the water).
What is a gradient?
You are probably referring to the "concentration gradient" on which substances travel during osmosis and diffusion. Concentration gradient - The change in concentration of a substance over distance or across a membrane. Concentration = amount Gradient = difference in concentration from one area to another.
How about blood glucose level?
fasting blood glucose <110 mg/dL Range ( 70-110 mg/dL plasma)