Bio 303 Final Review

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer? A.) Galactocerebroside' B.) Peripheral protein C.) Integral protein D.) Lipid-anchored protein E.) Phosphatidylcholine

C.) Integral protein

Which of these equation sets represents coupled reactions? - A + B --> C + D (DG = 5.4 kcal/mole) and E + F --> G + H (DG=+4.4 kcal/mole) - A + B -->C + D (DG = 5.4kcal/mole) and C + D --> E + F (DG = +4.4 kcal/mole) - A + B -->C + D (DG = 5.4kcal/mole) and E + F --> C + D (DG = +4.4 kcal/mole) - All are correct examples of coupled reactions

- A + B -->C + D (DG = 5.4kcal/mole) and C + D --> E + F (DG = +4.4 kcal/mole)

During active transport, the positive delta G created by moving something up its concentration gradient (to where it is already higher) is overcome by... - Coupling this movement with something with larger negative delta G, like ATP hydrolysis. -Coupling this movement with something with a large positive delta G, like phosphorylation. -Cells going to equilibrium - Passive transport of the moving substance back down the concentration gradient

- Coupling this movement with something with larger negative delta G, like ATP hydrolysis. Yo

As an action potential is initiated, the membrane is ___. This is caused by the ___ of ___ ions. - Depolarized, influx, Na+ -Hyperpolarized, efflux, Na+ -Depolarized, influx, Na+ -Hyperpolarized, influx, Na+ -Depolarized, efflux, Na+

- Depolarized, influx, Na+

Liposomes formed in water are impenetrable to water - that is, water cannot get in or out. If you made liposomes that contained lipids and the aquaporin protein complex (and assuming it was folded correctly), then moved the liposomes + aquaporin to a more hypotonic solution, what do you predict would happen? - Water would move out of the liposomes out of the aquaporin due to osmosis and cause the liposome to shrink or collapse. - The aquaporins would precipitate out of solution, leaving the liposomes in tact. -Water would not move into the liposome so they would stay the same. - Water would move out of the liposomes through the aquaporin due to osmosis and cause the liposome to shrink or collapse. - Water would move into the liposomes through the aquaporin due to osmosis and cause the liposome to swell or break open

- Water would move into the liposomes through the aquaporin due to osmosis and cause the liposome to swell or break open

Mammalian muscle cells have a significant a higher level of K+ inside the cells (140 mM) than outside (5nM). At a membrane potential of +40 mV, in which direction do K+ move through a leak channel? - Not sure because it may be against the electric gradient -From inside to outside - From outside to inside - Both directions with equal number of K+ moving in and out

-From inside to outside

Which of the following is not amphipathic? -Transmembrane protein -Sphingomyelin -Cholesterol -Unsaturated fatty acid tail -Phosphatidylcholine

-Unsaturated fatty acid tail

You discovered a new ion channel! You name it jolteon after your favorite electric-type pokemon. After extensive experiments, you determine that the selectivity pore has a stretch of partially positively charged amino residues in the center. Using patch-clamp experiments, you find that ions pass through the channel only when you apply a voltage. What type of channel is jolteon most likely to be? -ATP-gated cation channel. -Ligand-gated cation channel. -Mechanosensory anion channel. -Voltage-gated anion channel -A cation/anion antiport ATPase pump.

-Voltage-gated anion channel

In the absence of oxygen, how many carbons from 1 molecule of glucose (a 6-carbon sugar) enter the TCA cycle? A.) 0 B.) 1 C.) 2 D.) 3 E.) 6

A.) 0

On average, how many ATPs would be generated if 3 NADH and 4 FADH2 donated their electrons to the electron transport chain? A.) 17 B.) 7 C.) 14 D.) 12 E.) 42

A.) 17

Which of the following molecules do you expect to be the least soluble in water ? A.) a lipid B.) a globular protein normally found in the cytoplasm C.) DNA D.) all of the molecules listed are soluble in water E.) Magnesium chloride

A.) A lipid

What is caused by the inability of Na+ ion channels to open for several milliseconds after their inactivation? A.) A refractory period B.) Depolarization C.) Termination D.) Hyperpolarization E.) An action potential

A.) A refractory period

The ratio of AMP and ATP in the cell are inversely proportional. The relative amounts of each of these molecules regulates the amount of ongoing glycolysis versus gluconeogenesis. Which of the following statements about the regulation of glycolysis versus gluconeogenesis is true? A.) All of these statements about glycolysis and gluconeogenesis are correct B.) High levels of AMP increase the activity of an enzyme in glycolysis, known as phosphocfructokinase C.) High levels of ATP inhibit the activity of an enzyme in glycolysis, known as phosphocfructokinase D.) High levels of AMP decrease the activity of an enzyme in gluconeogenesis, known as fructose 1,6-biphosphatase

A.) All of these statements about glycolysis and gluconeogenesis are correct

A transport system that moves one solute into the cell and another one out of the cell during a single cell cycle accompanied by expenditure of energy through ATP hydrolysis could be called ___ A.) An active antiport B.) An active uniport C.) A passive antiport D.) An active symport E.) A passive symport

A.) An active antiport

Which part of a neuron conducts impulses away from the cell body toward the target cell(s)? A.) Axon B.) Terminal knob C.) Axon hillock D.) Cell body E.) Dendrites

A.) Axon

Which of the following best describes antibodies? A.) Bind specifically to a particular amino acid on an antigen

A.) Bind specifically to a particular amino acid on an antigen

_____ coated vesicles travel in the _____ direction carrying proteins that will be transported from the medial Golgi to the cis Golgi. A.) COPI, retrograde B.) COPII, retrograde C. clathrin, retrograde D. COPII, anterograde E.COPI, anterograde

A.) COPI, retrograde

Sickle cell anemia is caused by mutation of glutamic acid to valine in the protein hemoglobin. This mutation causes hemoglobin molecules to form long fibers which have a reduced capacity to carry oxygen and ultimately change the shape of the red blood cell. The structures of glutamic acid and valine are shown below, as are the structures of 5 other amino acids (labelled #1 -#5). Use the information provided and these structures to answer the question. Q.) Glutamic acid is a ___ amino acid, and therefore it likely participates in ___ when interacting with other amino acids. A.) Charged, ionic bonds B.) Polar, hydrogen bonds C.) Nonpolar van der Waals interactions D.) Charged, van der Waals interactions E.) Polar, ionic bonds

A.) Charged, ionic bonds

There are four protein complexes which make up the electron transport chain - complex I, complex II, complex III, and complex IV. Which of the following describes a unique property of complex II (also known as succinate dehydrogenase ) relative to the other complexes in the electron transport chain? A.) Complex II does not transport protons across the inner mitochondrial membrane B.) Complex II interacts with the electron carrier ubiquinone C.) Complex II is associated with the outer mitochondrial membrane D.) Complex II reduced oxygen to water in the final reaction of the electron transport chain

A.) Complex II does not transport protons across the inner mitochondrial membrane

A culture of Dictyostellium slime mold is prepared in which the myosin II gene is deleted. In which of the activities described below are these cells unable to participate? A.) Cytokinesis B.) Separation of chromosomes during mitosis and cytokinesis C.) Separation of chromosomes during mitosis D.) Cell elongation E.) Separation of chromosomes during mitosis and cell elongation

A.) Cytokinesis

You identify a new protein in a cancer cell that you predict localizes to the nucleus. You'd like to test this using microscopy. Which of the following approaches or tools will be useful for determining if your protein can be found in the nucleus? A.) Generate a GFP fusion with your protein and image it using fluorescence microscopy B.) Generate a GFP fusion with your protein and image is using transmission electron microscopy C.) Generate a fluorescent antibody that recognizes your protein and use this in scanning electron microscopy D.) Generate a fluorescent antibody that recognizes your protein and use this in bright field microscopy

A.) Generate a GFP fusion with your protein and image it using fluorescence microscopy

Identify the following cytoskeletal filament [see image in exam] A.) Intermediate filaments B.) Microtubules C.) Actin filaments D.) Muscle fibers E.) Elongated chromatids

A.) Intermediate filaments

You modify the gene for an integral membrane protein so that the cytoplasmic portions of the protein are deleted. When the gene is inserted in cells, what happens to the mobility of this protein in the membrane? A.) It moves much greater distances than the intact protein B.) It flips to the opposite leaflet C.) It moves much smaller distances than the intact protein D.) It does not move at all E.) None of the above

A.) It moves much greater distances than the intact protein

The sodium-potassium pump makes the cell interior more ___ by pumping ___ sodium ions out of the cell for every ___ potassium ions pumped in. A.) Negative, 3,2 B.) Negative, 2,3 C.)Positive 3,2 D.) Positive, 2,3 E.)None of the above

A.) Negative, 3,2

What happens after a subthreshold depolarization? A.) No action potential B.) No action potential C.) A reversal of the direction of the neural impulse D.) A partial action potential E.) A proportional action potential

A.) No action potential

What kind of forces hold microtubular structure together? A.) Noncovalent interactions B.) Covalent interactions C.) Hydrophobic bonds D.) Hydrogen bonds E.) None of the above

A.) Noncovalent interactions

When the MAP protein tau has abnormally high levels of ___, it is associated with the development of strange, tangled filaments called ___ that have been seen in the brains of patients suffering from several fatal neurodegenerative diseases like Alzheimer's. A.) Phosphorylation, neurofibrillary tangles B.) Phosphorylation, neurofibrillary plaques C.) Dephosphorylation, neurofibrillary tangles D.) Dephosphorylation, neurofibrillary plaques E.) Acetylation, neurofibrillary plaques

A.) Phosphorylation, neurofibrillary tangles

The electron transport chain establishes a proton gradient by : A.) Pumping protons from the mitochondrial matrix to the intermembrane space B.) Pumping protons from the intermembrane space into the mitochondrial matrix C.) Pumping protons from the mitochondrial matrix across the outer mitochondrial membrane D.) Pumping protons from the cytopalms into the intermembrane space

A.) Pumping protons from the mitochondrial matrix to the intermembrane space

Taxol is commonly used as an anticancer treatment. Why might this drug be an effective anticancer drug? A.) Taxol disrupts formation of the mitotic spindle by interfering with polymerization of microtubules. This would result in cell cycle arrest and/or cell death. B.) Taxol disrupts formation of mitotic spindle by interfering with polymerization of actin. This would result in cell cycle arrest and/or cell death. C.) Taxol disrupts actin polymerization and interferes with cytokinesis. This would prevent the cell from dividing and lead to cell death. D.) Taxol disrupts microtubule polymerization and interferes with cytokinesis. This would prevent the cell from dividing and lead to cell death.

A.) Taxol disrupts formation of the mitotic spindle by interfering with polymerization of microtubules. This would result in cell cycle arrest and/or cell death.

You are carrying out experiments in cell fusion by fusing together cells at different stages of the cell cycle. You then observe the behavior of each nucleus residing in the combined cytoplasm of the two cells. Which of the following responses would occur if you fused a G2 cell to a cell in the M phase? A.) The G2 nucleus would undergo premature chromosomal condensation, but the compacted chromosomes would be visibly doubled B.) The M phase nucleus would be affected in such a way that its complicated chromosomes decondense C.) The nucleus from the G2 cell would start to replicate its DNA D.) The G2 nucleus would undergo premature chromosomal condensation to form a set of elongated, single compacted chromosomes

A.) The G2 nucleus would undergo premature chromosomal condensation, but the compacted chromosomes would be visibly doubled

Which of the following describes part of the cell theory?

All organisms are composed of one or more cells.

Sickle cell anemia is caused by mutation of glutamic acid to valine in the protein hemoglobin. This mutation causes hemoglobin molecules to form long fibers which have a reduced capacity to carry oxygen and ultimately change the shape of the red blood cell. The structures of glutamic acid and valine are shown below, as are the structures of 5 other amino acids (labelled #1 -#5). Use the information provided and these structures to answer the question. Q.) Of the amino acids depicted (#1-#5), which one has the most similar properties to glutamic acid? A.) 1 B.) 2 C.) 3 D.) 4 E.) 5

B.) 2

You are studying the electron transport chain and are interested in comparing the activity of complexes I and III. In considering their different roles in the ETC, which of the following statements about complexes I and III are true? A.) Both complexes I and III transport protons to the intermembrane space B.) All of these statements about complexes I and III are true C.) Complex III receives electrons from ubiquinone D.) Complex I receives electrons from NADH E.) Complex III transfers electrons t cytochrome C

B.) All of these statements about complexes I and III are true

Which proteins (in term of their ultimate destination in the cell) need both a "signal" and a "receptor" to be properly transported? A.) A peripheral membrane protein of the cytosolic surface of the plasma membrane B.) An integral membrane protein of the ER C.) All of these proteins need both a signal and receptor to be properly tagged D.) Enzymes important for glycolysis E.) Cytosolic translation machinery

B.) An integral membrane protein of the ER

You synthesize a drug that binds to mitotic cyclin preventing its interaction with cdc2 kinase. You apply this drug to budding yeast. What do you think will be the result? A.) Cells will arrest at the G1-S checkpoint B.) Cells will arrest at the G2-M checkpoint C.) Cells will proceed through mitosis D.) Cells will arrest at the spindle assembly checkpoint

B.) Cells will arrest at the G2-M checkpoint

You are studying the metastatic potential (the likelihood of metastasis) of a series of primary tumors derived from patients. You isolate RNA from these cells and analyze the expression of genes encoding ECM components and cell adhesion molecules, especially E-cadherin. Which of the following would you expect for cells most likely to metastasize? A.) Cells with a higher likelihood of metastasis will have high E-cadherin expression B.) Cells with a higher likelihood of metastasis will have low E-cadherin expression C.) E-cadherin is not a good marker to evaluate, it is not expected to be different between cells or differing metastatic potential

B.) Cells with a higher likelihood of metastasis will have low E-cadherin expression

A motor protein is tagged and observed to move a long distance towards the cell body in neurons. Which motor protein is this most likely to be? A.) Keratin B.) Dynein C.) Myosin II D.) Myosin V E.) Kinesin

B.) Dynein

The glycerol phosphate shuttle is used to transfer electrons from a reduced electron carrier generated during glycolysis to the electron transport chain. Which of the following statements about the glycerol phosphate shuttle is true? A.) Electrons from the reduced electron carrier NADH are donated to a molecule which is able to cross the inner mitochondrial membrane. B.) Electrons from the reduced electron carrier NADH are donated to a molecule which is able to cross the outer mitochondrial membrane C.) The electrons from the reduced electron carrier NADH are donated directly to FAD+ and the reduced form, FADH2, is able to cross the inner mitochondrial membrane D.) The electrons from reduced electron carrier NADH are donated directly to FAD+ and the reduced form, FADH2, is able to cross the outer mitochondrial membrane.

B.) Electrons from the reduced electron carrier NADH are donated to a molecule which is able to cross the outer mitochondrial membrane

Which of the following statements about mitochondria is NOT true? A.) All of these statements about mitochondria are true B.) If oxygen is not available, mitochondria convert pyruvate to lactate with enzymes in the inner mitochondrial membrane C.) Mitochondrial function may be linked to aging D.) Mitochondria can divide by fission E.) Mitochondria contain their own DNA and ribosomes

B.) If oxygen is not available, mitochondria convert pyruvate to lactate with enzymes in the inner mitochondrial membrane

You are working on developing a treatment for blood clots, and you are investigating the use of the RGD peptide to prevent clot formation in platelets. You know that platelet aggregation is driven by the fibrinogen protein and its interaction with a transmembrane protein on the cells. The addition of the RGD peptide appears to prevent platelet aggregation and clot formation in vitro. Which of the following proteins do you think the fibrinogen is interacting with to promote platelet aggregation and clot formation? A.) Fibronectin B.) Intergrins C.) Proteoglycns D.) Cadherins E.) Collagen

B.) Intergrins

Movement past the transition point near the end of G2 that moves cells on to mitosis requires cdc2 activation by ____. A.) Na+ ions B.) Mitotic cyclins C.) p53 D.) p21 E.) G1 cyclin

B.) Mitotic cyclins

What evidence suggests a cell spends most of its time in interphase? A.) Interphase is more useful B.) Only a small percentage of cells in a tissue or cell culture are seen to be in mitosis at any given time C.) A large percentage of cells in tissue or cell culture are seen to be in mitosis at any given time D.) Mitosis is too intricate a process to last very long

B.) Only a small percentage of cells in a tissue or cell culture are seen to be in mitosis at any given time

Consider the following electron micrograph of a sarcomere [see electron graph of sarcomere on exam / general diagram of a sarcomere]. Which region depicts the A band? A.) Region 1 B.) Region 2 C.) Region 3 D.) Region 4

B.) Region 2

Neurodegenerative disorders such as mad cow disease, Alzheimer's, Parkinson's and other diseases, protein misfolding leads to the accumulation of protein aggregates in neurons. These proteins often undergo a transition in which alpha helix is converted to beta sheet. At which level of protein structure is this change occurring? A.) Primary B.) Secondary C.) Tertiary D.) Quaternary E.) There is not enough information to determine

B.) Secondary

Which of the following treatments do/does not disassemble microtubules in living cells? A.) Elevated Ca2+ ion concentration B.) Slightly elevated temperature C.) Hydrostatic pressure D.) Colchicine or vinblastine treatment E.) All of these choices disassemble microtubules in living cells

B.) Slightly elevated temperature

Which of the following statements regarding cellular structures and cell size is most accurate?

Bacteria are more similar in size to eukaryote mitochondria than they are to eukaryotic cells.

Which of the following are the net products of glycolysis starting with 1 molecule of glucose? A.) 2 pyruvate, 4 ATP, 2 NADH, 2 H+ B.) 2 Pyruvate, 2 ATP, 4 NADH, 4H+ C.) 2 pyruvate, 2 ATP, 2 NADH, 2 H+ D.) 1 pyruvate, 2 ATP, 4 NADH, 4 H+ E.) 1 pyruvate, 2 ATP, 4 NADH, 2 H+

C.) 2 pyruvate, 2 ATP, 2 NADH, 2 H+

Sickle cell anemia is caused by mutation of glutamic acid to valine in the protein hemoglobin. This mutation causes hemoglobin molecules to form long fibers which have a reduced capacity to carry oxygen and ultimately change the shape of the red blood cell. The structures of glutamic acid and valine are shown below, as are the structures of 5 other amino acids (labelled #1 -#5). Use the information provided and these structures to answer the question. Q.) Of the amino acids depicted (#1-#5), which one is the most likely to cause a similar disruption to hemoglobin structure as the valine mutation? A.) 1 B.) 2 C.) 3 D.) 4 E.) 5

C.) 3

Which of the following is normally associated with the cilia of organisms from protists to mammals? A.) A 9+0 pattern B.) A 9+1 pattern C.) A 9+2 pattern D.) A 9+3 pattern E.) None of these choices

C.) A 9+2 pattern

Which of the following describe a major function of the extracellular matrix? A.) Provide a biomechanical force B.) Control cell migration C.) All of the answers describe functions of the extracellular matrix D.) Act as a signal for small signaling molecules E.) Anchor cells to a basement membrane or other cells

C.) All of the answers describe functions of the extracellular matrix

Which of the following molecules is able to pass through the plasma membrane without being meditated by a protein? A.) Potassium ions B.) Glucose C.) Carbon dioxide D.) Acetylcholine E.) Chloride ions

C.) Carbon dioxide

The three catalytic sites of ATP synthase _____ A.) Have the same binding affinity for the reaction substrates B.) Are each in the same conformation at any given time C.) Have different product binding affinities D.) None of these statements about the catalytic sites in ATP synthase are true E.) Each exclusively act as either of three binding conformations (open, loose, or tight) and cannot transition between comformations

C.) Have different product binding affinities

In the absence of oxygen, muscle cells reduce pyruvate to lactate and oxidize NADH to NAD+. In what cellular compartment do these reactions take place? A.) In the mitochondrial matrix B.) In the inner mitochondrial membrane C.) In the cytoplasm D.) In the reducing environment of the endoplasmic reticulum E.) In the intermembrane space of the mitochondria

C.) In the cytoplasmY

What kind of membrane protein is found entirely outside the bilayer on either the extracellular or cytoplasmic surface and is covalently linked to a membrane lipid situated in the bilayer? A.) Integral protein B.) Transmembrane C.) Lipid-anchored protein D.) Peripheral proteins E.) Carbohydrate-anchored protein

C.) Lipid-anchored protein

Which of the following lists best describes all of the main products released during one round of the TCA cycle? A.) NADH, ATP, CO2 B.) Pyruvate, ATP, NADH, H2O C.) NADH, FADH2, GTP, CO2 D.) Pyruvate, GTP, NADH, FADH2

C.) NADH, FADH2, GTP, CO2

What is thought to be important in maintaining the native structure of the Kv channel membrane protein and promoting its function as a voltage-gated channel? A.) Negatively charged cholesterol B.) positively charged sphingolipids C.) Negatively charged phospholipids D.) Positively charged phospholipids E.) Negatively charged sphingolipids

C.) Negatively charged phospholipids

You have identified a new cell type that forms within gut tissue. You are trying to determine the extent of communication between cells. You inject a single cell with the dye fluorescin. After a brief period of time, the dye spreads to cells neighboring the injected cell. What do you conclude? A.) The cells are connected by tight junctions B.) The cells contain focal adhesions C.) The cells are connected by gap junctions D.) The cells are connected by hemidesomosomes E.) The cells are connected by aherens junctions

C.) The cells are connected by gap junctions

Consider the following diagram [diagram of yeast cell cyclin/kinase cell cycle pathway]. What do you predict would happen in yeast that had a mutation in cdc2 kinase that prevented its binding to cyclin? Note: there are no other mutations. A.) The mutant yeast would go through the cell cycle with no change compared to normal yeast B.) The mutant yeast would enter mitosis early, producing smaller yeast cells C.) The mutant yeast would remain in interphase D.) The mutant yeast would divide later to make larger yeast cells

C.) The mutant yeast would remain in interphase

Where are hydrophobic interactions most likely to occur in the cell? A.) On the surface of a protein with many amino acids B.) Between the sugar-phosphate backbone of DNA and a transcription factor that binds DNA C.) Within the core of a globular protein normally found in the cytoplasm D.) Between an amino acid with a charged side chain and water molecules E.) Between a charged phospholipid head group and a charged amino acid on the surface of a protein

C.) Within the core of a globular protein normally found in the cytoplasm.

You genetically engineer nonadhesive cells to express E-cadherin and you mix them with another set of cells expressing P-cadherin. You have labelled the E-cadherin expressing cells with the fluorescent protein GFP (green) and the P-cadherin expressing cells with the protein RFP (red). You mix the cells together and moniter their interactions. What do you observe? A.) There is a random distribution of red and green cells, including clusters of only red cells, clusters of only green cells, and clusters with both red and green cells equally mixed. B.) Each red cell is interacting with one green cell, make an alternating and organized pattern of red and green cells within the group of cells C.) Within the group of cells, one half is all red cells and the other half is all green cells D.) The expression of different cadherins on different cells causes them all to die

C.) Within the group of cells, one half is all red cells and the other half is all green cells

In a process known as the warburg effect, cancer cells use aerobic glycolysis to generate ATP. In a cancer cell using only glycolysis to generate ATP. How many ATP are generated for one molecule of glucose? A.) 6 B.) 4 C.) 36 D.) 2 E.) 12

D.) 2

You pulse label cells in an asynchronous culture for 20 seconds with radioactive thymidine that gets incorporated into newly synthesized DNA. You immediately wash and fix the cells. Using a microscope, you observe that 10% of the cells are radioactively labeled and 20% of the cells have unlabeled mitotic chromosomes. The cell cycle is 50 hours. How long is the S phase? A.) 15 hours B.) 30 minutes C.) 10 hours D.) 5 hours

D.) 5 hours

Which of the following strategies are used in the cell to promote reactions with a large DGo' to occur? A.) The reaction may be coupled to ATP hydrolysis B.) The reaction may be coupled to an energetically favorable reaction C.) The cellular concentration of the reactants may increase to promote the reaction D.) All of these strategies may be used by the cell E.) The cellular congregation of the products may decrease to promote the reaction

D.) All of these strategies may be used by the cell

Which of the following does NOT describe the types of microfilament organization normally seen in cells? A.) Ordered arrays B.) Highly branched networks C.) Tightly anchored bundles D.) Cylindrical conglomerations E.) All of these choices describe types of microfilament organization

D.) Cylindrical conglomerations

What is the direct source of energy that powers molecular motors? A.) Hydrolysis of GTP B.) An H+ gradient C.) A proton gradient D.) Hydrolysis of ATP E.) None of the above - motors proteins do not need a source of energy

D.) Hydrolysis of ATP

Given a chemical reaction in which DGo' is positive, under what conditions could this reaction be made energetically favorable in a cell? A.) If the cell links the reaction to one with a common intermediate and positive DGo' B.) If the concentration of ATP in the cell decreases C.) This reaction will never be energetically favorable in a living cell D.) If the cell maintains a 10-fold higher concentration of reactant than product E.) If the cell maintains a 30-fold higher concentration of product than reactant

D.) If the cell maintains a 10-fold higher concentration of reactant than product

When is the kinetochore assembled on the centromere? A.) Metaphase B.) Interphase C.) Anaphase D.) Prophase E.) Telophase

D.) Prophase

The limit of resolution of a light microscope is 200 nm. What does this mean? A.) Structures bigger than 200 nm, like bacterial cells or mitochondria, will have poor resolution when viewed with light microscopy. B.) The use of fluorescent proteins improves the limit of resolution of light microscopes C.) The limit of resolution is better than that of a transmission electron microscope D.) Structures smaller than 200 nm, like ribosomes or the lipid bilayer, will have poor resolution when viewed with light microscopy.

D.) Structures smaller than 200 nm, like ribosomes or the lipid bilayer, will have poor resolution when viewed with light microscopy.

Collagen provides strength and structure to the extracellular matrix. Which of the following properties is important for collagen to be able to provide strength to the ECM? A.) The formation of extensive beta sheet structures B.) The double helix structure of collagen C.) The removal of post-translational modifications that inhibit interactions between collagen fibroids D.) The addition of post-translational modifications which strengthen interactions between collagen fibrils E.) All of the answers describe properties that make collagen strong

D.) The addition of post-translational modifications which strengthen interactions between collagen fibrils

While culturing some cells, you lower the temperature of the culture. What happens immediately to the membrane fluidity? A.) Nothing happens because fluidity does not change in cultured cells. B.) Nothing, because temperature does not affect fluidity C.) The membrane becomes more fluid D.) The membrane becomes less fluid

D.) The membrane becomes less fluid

What kind of organism reaches equilibrium? A.) A hibernating organism B.) One with a low metabolic rate C.) Cancer cells D.) One that is actively metabolizing E.) A dead organism

E.) A dead organism

Which of the cells below normally possess a relatively high level of mitotic activity? A.) Stem cells of various adult tissues B.) Hematopoietic stem cells that give rise to red and white blood cells C.) Stem cells at the base of numerous epithelia that line the body cavities D.) The relatively unspecialized cells found near the tips of plant roots and stems E.) All of the above

E.) All of the above

A small zone of fluorescent microtubules in a cell is photobleached so that their fluorescent label gives off no light. Some time later fluorescence returns to the bleached zone in the cell. Which of the following is a possible explanation for the recovery of fluorescence in the region of the cell previously bleached? A.) The dynamics of the microtubules turning over in that bleached zone B.) The growth of new microtubules into the bleached zone C.) The movement of microtubules through the bleached zone D.) The dynamics of the microtubules turning over in that bleached zone and the growth of new microtubules into the bleached zone E.) All of these choices

E.) All of these choices

With which of the following structures are intermediate filaments associated? A.) The nuclear envelope in the center of the cell B.) Hemidesmosomes C.) Desmosomes D.) The neurofilaments of neural axons E.) All of these choices are correct

E.) All of these choices are correct

What kind of interactions are normally involved in the binding of a substrate to an enzyme's active site? A.) Hydrogen bonds B.) Ionic bonds C.) van der Waals interactions D.) covalent bonds E.) Multiple types of interactions including iconic bonds, hydrogen bonds and and van der Waals interactions

E.) Multiple types of interactions including iconic bonds, hydrogen bonds and and van der Waals interactions

People who have the O blood type possess ______ A.) An enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids. B.) An enzyme that adds a galactose to the end if the oligosaccharide chain on RBC membrane glycolipids C.) Both an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids and an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids. D.) An enzyme that adds phospholipids to the end of the oligosaccharide chain on RBC membrane glycolipids. E.) No enzymes capable of attaching galactose or N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids.

E.) No enzymes capable of attaching galactose or N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids.

Which of the following is true about action potentials? A.) All cells generate action potentials. B.) The magnitude of depolarization determines the strength of an action potential. C.) Action potentials are only propagated in myelinated cells. D.) Two of these statements are true E.) None of the above

E.) None of the above.

You have identified a new protein that has quaternary structure. What types of bonds do you predict will help to maintain this quaternary structure? A.) Hydrogen bonds B.) Ionic bonds C.) Van der Waals interactions D.) Quaternary structure is only maintained by covalent bonds between R groups of amino acids E.) Quaternary structure is maintained by ionic bonds, hydrogen bonds, and van der Waals interactions

E.) Quaternary structure is maintained by ionic bonds, hydrogen bonds, and van der Waals interactions

What part of the molecular motor kinesin is responsible for binding to the cargo to be hauled? A.) The neck B.) The motor domain C.) The rod-like stalk D.) The motor domain and the neck E.) The fan-shape tail

E.) The fan-shape tail

You fuse a goat cell and a rabbit cell and then treat the cell with anti-goat or anti-rabbit protein-directed antibodies that are covalently linked to fluorescent dyes (antibodies to goat proteins show green fluorescence, antibodies to rabbit proteins show red fluorescence). What does the cell look like after 2 hours? A.) The cell is half red and half green B.) The cells appear to be yellow in color C.) There is not fluorescent signal D.) The red and green labels are distributed in intermingled patches E.) The red and green labels are uniformly distributed across the entire membrane

E.) The red and green labels are uniformly distributed across the entire membrane

An enzyme catalyzed reaction proceeds at a faster rate than an uncatalyzed reaction because the enzyme lowers the difference in free energy between the reactants and the products. True False

False

Enzyme catalyzed reactions proceed at a faster rate than non-catalyzed reactions because an enzyme's active site binds poorly to the transition state, which causes it to generate product faster. True False

False

In both prokaryotes and eukaryotes, there is a nuclear membrane surrounding the DNA. True False

False

Which of the following is not a shared feature of prokaryotes and eukaryotes?

The presence of organelles such as the ER and golgi.

A temperature sensitive mutation in the gene encoding for a protein required for COPI vesicle formation in the cis-Golgi has been identified in yeast. When the yeast cells are grown at the restrictive temperature, some resident ER proteins are retained in the cis-Golgi. True False

True

The F0 subunit of the ATP synthase is located in the inner mitochondrial membrane True False

True

The beta subunits of ATP synthase have three binding sites that exist in open, tight, and loose conformations which differ based on their binding affinity to ATP and ADP+Pi. True False

True

The effect of competitive inhibitors on enzyme-catalyzed reactions can be overcome by increasing the substrate concentration. True False

True

How is a nerve impulse usually transmitted across a synapse from a presynaptic to a postsynaptic cell? Via neurotransmitter Via plasmodesmata Via Na+ ions Via direct connection

Via neurotransmitter

Which of the proteins below are NOT synthesized on the membrane-bound ribosomes of the rough ER? a. proteins that reside in the inner mitochondrial membrane b. soluble lysosomal proteins c. integral membrane proteins of the plasma membrane d. secreted proteins that comprise the extracellular matrix e. All of these are synthesized on rough ER-associated ribosomes

a. proteins that reside in the inner mitochondrial membrane

You identify a new organelle in the cell which you determine is a hub for a certain class of proteins called Retrievers. You name this organelle UMBC. In the Retriever proteins, you identify a short sequence which you think is responsible for targeting these proteins to UMBC. You name this sequence UTS (UMBC Targeting Sequence). Which of the following experiments will tell you if UTS is necessary for Retriever targeting to UMBC? a. Deletion of the genes encoding Retriever proteins causes UMBC to disappear b. Fusion of UTS to GFP turns UMBC green using fluorescence microscopy c. Deletion of the UTS sequence from Retriever causes Retriever to be primarily localized to the cytoplasm d. The addition of basic amino acids to UTS causes Retriever to localize to UMBC e. Fusion of UTS to GFP turns mitochondria green using fluorescence microscopy

c. Deletion of the UTS sequence from Retriever causes Retriever to be primarily localized to the cytoplasm

Which of the following sequences targets a protein to the peroxisome? N-terminal sequence containing 3 nonconsecutive lysines and 1 arginine :a. the addition of mannose 6-phosphate b. N-terminal sequence containing 3 nonconsecutive lysines and 1 arginine c. N-.....Thr-Gly-Val-Pro-Gly-Ser-Gly-Ser-Lys-Leu-C d. a KDEL sequence e. an internal set of one or two regions that contain 5 residues of Lys and Arg each

c. N-.....Thr-Gly-Val-Pro-Gly-Ser-Gly-Ser-Lys-Leu-C

You are studying a receptor at the plasma membrane that binds to a growth hormone known as EGF. It is endocytosed into the cell when EGF binds the receptor. Of the following components, which one does NOT participate in edocytosis of the EGF receptor? a. dynamin b. clathrin c. Sar1 d. AP2 adaptor protein e. All of these components are involved in endocytosis of the receptor

c. Sar1

As vesicles bud off the ER, some of the ER resident proteins get transported to the cis-Golgi. These proteins need to return to the ER in order to perform their function. Which of the following factors is required for returning ER resident proteins to the ER from the cis-Golgi? a.) All of the factors listed are required b.) Sar1 c.) a receptor that recognizes the sequence KDEL d.) COPII proteins e.) clathrin

c.) a receptor that recognizes the sequence KDEL

When clathrin coated pits form at the plasma membrane, the AP2 adaptor protein interacts with the phosphoinositide phosphate lipid PI(4,5)P2, also known as PIP2. What is the purpose of the interaction between the AP2 adaptor and PI(4,5)P2 at the plasma membrane? a. PI(4,5)P2 helps to promote membrane curvature in the presence of the AP2 adaptor b. PI(4,5)P2 directly interacts with the C-terminal tail of cargo receptors to recruit them to the coated pit c. PI(4.5)P2 directly recruits clathrin to the coated pit d. PI(4,5)P2 is a unique phosphoinositide located in the plasma membrane and it helps to recruit the AP2 adaptor specifically to the plasma membrane

d. PI(4,5)P2 is a unique phosphoinositide located in the plasma membrane and it helps to recruit the AP2 adaptor specifically to the plasma membrane

Which of the following components are required for a secretory protein being synthesized on the rough ER to be translocated into the ER lumen? a. The BiP chaperone b. signal recognition particle c. the translocon pore d. SRP receptor e. All of these components are required.

e. All of these components are required.

_____ coated vesicles travel in the _____ direction carrying proteins from the trans Golgi network to lysosomes. a. COPII, anterograde b. COPII, retrograde c. COPI, anterograde d. clathrin, retrograde e. clathrin, anterograde

e. clathrin, anterograde