MCB Exam #2

You can tell if it is spontaneous when the reaction by itself. The key factor is the free energy change, if the G is negative it symbolizes that the reaction is spontaneous. Usually slow, If it is not spontaneous it requires some energy.

How can we tell if a chemical reaction is spontaneous or not?

Hormone passes through the cell membrane and into the nucleus where it binds estrogen receptors. The estrogen-receptor complex binds DNA and regulates gene activity (or to be exact, gene transcription) Ex: estrogen and aldosterone - both are steroid hormones.

How do intracellular receptors work? Examples?

Botox works by releasing the botulinum toxin into the face which prevents the acetylcholine from mocking and decreases the movement of the facial muscles.

How does Botox work?

It works by interfering with the building of the cell walls.

How does penicillin work to kill bacteria?

Peroxisomes break down molecules by adding or removing hydrogen, creating H202 as a byproduct. Has enzymes called Catalse(R2H2) that breaks down H202 into water and oxygen.

How is H2O2 generated in peroxisome? What is the enzyme in the peroxisome to break down the harmful H2O2?

Through a transporter protein and facilitated diffusion. The glucose binds to a GLUT and then the GLUT switches directions and releases the glucose to the other side.

How is glucose transported into a cell? By which protein?

Through retrograde axonal transport with dynein.

How is tetanus toxin transported in infected nerve cells?

In a hypertonic solution, the cell would lose water and become crenated. Water would move out of the cell In a hypotonic solution, the water would move into the cell, and it would become hemolyzed and burst.

If a cell is placed into a hypertonic (or hypotonic) solution, what happens to the cell? What molecules move across the membrane in which direction?

Mitochondria are inherited only through females.

In most cases, one's mitochondrial DNA is inherited from which parent?

tight junctions

Junctions between adjacent cells in a layer that prevent the leakage of material between cells.

nervous tissue

Receives, generates and conducts electrical signals.

active transport

Requires energy- up or against gradient

passive transport

Requires no input of energy- down or with gradient

cardiac muscle

Responsible for contraction of the heart; intercalated disc (contains desmosomes and gap junctions).

smooth muscle

Responsible for involuntary body activities, such as contractions of the digestive tract and arteries; spindle shaped.

skeletal muscle

Responsible for voluntary movement; long muscle cells.

paracrine

Signal does not affect the originating cell but influences nearby cells.

endocrine

Signals enter the blood and usually travel long distance.

connective tissue

Support the body or connect tissues.

uniporter

Transports one single ion or molecules.

antiporter

Two or more ions or molecules transported in opposite directions.

symporter

Two or more ions or molecules transported in the same direction.

Centrosome- the "microtubule- organizing center" Centrioles-Half of the centrosome

What are centrioles and centrosomes? Function?

They both use energy and are used to transport large molecules such as proteins and polysaccharides.

What are endocytosis and exocytosis? Do they use energy?

Light microscope- 0.2um Electron microscope- 2nm Difference- the electron microscope is 100 times better. It uses the beams of electrons for illumination and has a shorter wavelength.

What are the approximate resolutions of a light microscope and an electron microscope? Why is the difference?

epithelial tissue, connective tissue, nervous tissue, & and muscle tissue

What are the four types of animal tissues?

Receptor Channel: Acetylcholine & Glutamate G-protein: Epinephrine & Histamine Receptor Enzyme: Growth Factor & Insulin Integrin Receptor

What are the four types of receptors we introduced in class? Examples of signal molecules for each type?

Simple Diffusion Facilitated Diffusion Active Transport Exocytosis and Endocytosis

What are the four types of transport mechanisms across the membrane?

Two K are coming into the cell but there are three NA going out.

What are the functions of the Na+-K+ Pump? (how many ions in which direction)

Mainly binds and supports other tissues. Contains packed cells scattered throughout an extracellular matrix. The matrix consists of fibers in a liquid, jellylike, or solid foundation, all made of protein. Connective tissue includes adipose tissue, blood, bone, cartilage, etc.

What are the general functions of connective tissue? Examples introduced in class?

Bacteria- Prokaryotes Archaea- Prokaryotes Eukarya- Eukaryotes

What are the three domains of life? Which ones are prokaryotes and eukaryotes?

ATP can be coupled to another reaction through ATP hydrolysis. This is spontaneous.

What is ATP-coupling?

It is the energy required for a reaction to start. The enzymes lower the activation energy.

What is activation energy? How is it related to enzymes?

Enzymes are protein catalysts. Enzymes make the chemical reaction go faster. It refuses the barrier so the reactions can "race" to the other side. Lower activation energy.

What is an enzyme? What does an enzyme do to a biological reaction?

contains desmosomes and gap junctions.

What is an intercalated disc? It is made of which types of cell junctions?

What is contained in the nucleus is genetic material- like DNA, chromatin, chromosomes, and nucleolus.

What is contained in the nucleus?

Glycolysis is the breaking down of glucose. This happens in the cytosol.

What is glycolysis? Where in the cell does it occur? What is its product?

Mitochondria/chloroplast entered bacteria cell, and divided with the dividing cell

What is proposed in the endosymbiont theory?

It is made up of a large subunit and a small subunit. The function of the ribosome is a complex RNA and protein used to synthesize proteins.

What is ribosome made of? Function of ribosome? How/where is a new ribosome made?

They only work on specific substrates- only one can be catalyzed because of the specific site for the substrate.

What is the ability of baker's yeast to utilize lactose, fructose, or sucrose? Why so?

The active site of an enzyme is the location where substrates bind to enzyme and reaction takes place.

What is the active site of an enzyme?

Typical bacterial cell- 1-10um Plant/animal cell- 10-100 um

What is the approximate diameter of a typical bacterial cell, or an animal/plant cell?

The cause of cystic fibrosis is caused when the CFTR (cysitic fibrosis transmembrane conductance regulator) mutates. The ions are the chloride ions. They may not have a channel or it isn't working which causes it.

What is the cause of cystic fibrosis (which ion, which gene, function of the gene product)?

0.9 % NaCl, this is because the concentration is similar to human blood and the fluid stays in the intravascular space and does not cause fluid movement between the body.

What is the content of normal saline?

Channels can open or close (have a gate). When it is open ions can go across the protein from high to low concentration. There is an open passageway for direct diffusion. Transporters bind to the solute and change its shape so it is facing the other side The difference is that the carrier is never open to both sides at the same time. But the channel is open to both sides.

What is the difference between a channel protein and a transporter protein?

transmission electron microscope (TEM)- uses the same principle as a light microscope- focus a beam of light through a specimen. The electrons penetrate through the sample. 2-D. A picture has different densities. scanning electron microscope (SEM)- Focus a beam of electrons onto a surface of a specimen, so the electrons will reflect off of the specimen. It gives images that look 3-D.

What is the difference between a transmission electron microscope and a scanning microscope? Be able to tell the difference between images obtained from TEM and SEM.

Chromatin- the relaxed form of DNA/ protein complex. When cells are not dividing. Chromosome- condensed form of DNA/protein complex; before and during cell division.

What is the difference between chromatin and chromosome?

Primary active transport- uses a pump and directly uses energy to transport solute(s). Uses ATP. Secondary active transport uses a different gradient and uses energy to establish a gradient to drive transport. Indirectly uses ATP.

What is the difference between primary active transport and secondary active transport?

Smooth ER: Lacks ribosomes, detoxification, carbohydrate metabolism , calcium balance, synthesis, and modification of lipids. Rough ER: Attached with ribosomes, involved with protein synthesis and sorting. Used to make membrane protein.

What is the difference between smooth ER and rough ER, in terms of structure and function?

catalase, its function is to break down H202 into water and oxygen

What is the enzyme that prevents the graying process of human hair? What is its chemical function?

Chloroplasts are the site of photosynthesis, they reproduce somewhat independently of the cell. Binary fission.

What is the function and reproduction method of chloroplast?

Mitochondria produces ATP for the cell, and they reproduce using binary fission, contain their own DNA and have an inner/outer membrane.

What is the function and reproduction method of mitochondria?

Three functions: Secretion, processing, and protein sorting

What is the function of the Golgi apparatus?

Oxidation of fatty acids, ethanol and other compounds. Breakdown of toxic molecules such as H2O2 Breakdown of synthesis of organic molecules

What is the function of the peroxisome?

Glucose goes through cellular respiration to produce CO2 and water. It occurs in the mitochondria.

What is the overall chemical reaction underlying cellular respiration? Where does it happen?

6 CO2 + 6 H2O + Light Energy -> C6H12O6 + 6O2

What is the overall chemical reaction underlying photosynthesis?

There is passive transport: Requires no input of energy- down or with gradient Simple diffusion: Diffusion of a solute through a membrane without transport protein Facilitated diffusion: Diffusion of a solute through a membrane with the aid of a transport protein. Active transport: Requires energy- up or against gradient

What is the transport mechanism for O2 and CO2 to move across the cell membrane?

Network of Membranes: enclosing the nucleus, endoplasmic reticulum, golgi apparatus, lysosomes, and vacuoles. May be directly connected to each other or pass materials via vesicles.

What structures and organelles are included in the endomembrane system?

They cover the outside of the body and line the organs and cavities within the body.

Where are epithelial tissues found?

Hydrophobic: signal molecules to bind to intracellular receptors. Hydrophilic: signal molecules bind to membrane receptors

Where are the two general locations of receptors? What determines the location?

Hydrophobic or small molecule

Which types of molecules can diffuse across the cell membrane?

Active Transport and Exocytosis require energy Simple Diffusion and Facilitated Diffusion do not require energy

Which types of transport require energy input and which ones don't?

Simple Diffusion does not require protein Facilitated Diffusion, Active Transport, and Exocytosis and Endocytosis all require protein

Which types of transport require protein and which one doesn't? Examples of cargo molecules?

They are essential to the health of humans and other vertebrates but cannot be synthesized by these animals and must therefore be obtained by the diet.

Why are vitamins important in our food?

Cytoplasm

everything between the cell membrane and the nucleus- including the cytosol.

phagocytic vacuole

holds food for bacteria

nucleolus

place in the nucleus where ribosome subunits are synthesized and assembled.

central vacuole

plants for storage of organic molecules, and the accumulation of water.

contractile vacuole

prevents the cell from absorbing too much water and possibly lysing

nucleus

structure in a cell containing genetic material.

ATP is only produced in glycolysis step.

At which step is ATP generated in fermentation?

anchoring junctions

Cell junctions that hold adjacent cells together or attach cells to the ECM. (like velcro) Anchoring junctions are mechanically strong.

epithelial tissue

Cells joined together forming continuous sheets to cover or line body surfaces.

autocrine

Cells secrete signaling molecules that bind to their own cell surface.

Similarities: Have cell membrane, cytoplasm, ribosomes, Have DNA. Prokaryotic cells: Small and simple, 1-10 um in size, Unicellular, The nucleus is absent, Lack of membrane bound organelles. Eukaryotic: Large and complex, 10-100 um in size, Unicellular or multicellular, Nucleus is present and has membrane-bound organelles.

Comparing prokaryotic and eukaryotic cells, what are the similarities and differences?

Inside of the plasma membrane: Cytoplasm- contained within plasma membrane Nucleoid region- where DNA is located Ribosomes- synthesize proteins Outside of the plasma membrane: Cell wall- provides support and protection

Describe the general structure of a bacterial cell.

ATP is the cell's energy shuttle. It is composed of ribose, adenine, and three phosphate groups.

Describe the structure and functions of ATP.

facilitated diffusion

Diffusion of a solute through a membrane with the aid of a transport protein.

simple diffusion

Diffusion of a solute through a membrane without transport protein

muscle tissue

Generates force that facilitates movement

Cytosol

The aqueous component of the cytoplasm of a cell, within which various organelles and particles are suspended. (the solution)

Microtubules: Long hollow cylindrical structures, Largest diameter, monomer-tubulin. Intermediate filaments: Intermediate in size, Various monomers, Form twisted, ropelike structures. Actin filaments: Long, thin fibers, Monomer: actin, Smallest diameter.

What are the three main types of cytoskeleton? Know the monomers for microtubule and microfilament.

Signal reception (by binding to receptor) Signal transduction Cellular response (change protein functions, change gene function)

What are the three stages of cell signaling?

Cell Wall, chloroplast, and central vacuole.

What are the three structures found in plant cells but not in animal cells?

skeletal muscle, smooth muscle, and cardiac muscle

What are the three subtypes of muscle tissue?

anchoring junctions, tight junctions, & gap junctions

What are the three types of cell junctions and their functions?

Neurons, or nerve cells, that transmit nerve impulses. Glial cells, or glia, that help nourish, insulate, and replenish neurons.

What are the two general cell types in nervous tissue?

Kinesin and Dynein

What are the two motor molecules and the cytoskeleton involved in axonal transport in neurons?

Actin and Myosin

What are the two proteins involved in muscle contraction?

Light reactions: use light energy, produce ATP, NADPH and O2, & take place in thylakoid membranes. Calvin cycle (dark reactions): occurs in the stroma, & uses ATP and NADPH to incorporate CO2 into carbohydrates.

What are the two stages of photosynthesis? Locations?

Anaerobic cellular respiration (fermentation) Aerobic cellular respiration

What are the two types of fermentation? Products?

Temperature and ionic conditions affect enzyme activity.

What environmental factors/conditions affect enzyme activity?

Catalyzes the replacement of GDP by GTP on the Gå subunit, which leaves to the dissociation of Gby dimer from Gå.

What happens to a G protein after the GPCR is activated?

gap junctions

allows ions/small molecules to pass through channels formed by connexon protein cylinders. Allows for intracellular communication

coenzymes

an organic cofactor. Many vitamins work as coenzymes.

endocytosis

as the plasma membrane folds inward to form a vesicle that brings substances into the cell. Comes into the cell.

nucleoid

bacterial structure where DNA is found in the cell.

cofactor

nonprotein enzyme helpers. May be inorganic (such as an ion) or organic.

myosin

the motor protein and creates muscle contraction

dynein

transport cargo from the axon terminal back to the cell body, retrograde transport.

kinesin

transport the cargo from the cell body to the axon terminal- anterograde transport.

actin

what they are sliding in between

exocytisis

when the material inside the cell packages into vesicles and excretes into the extracellular medium. All neurotransmitters are released by exocytosis.