Exam 2 Questions Flashcards by Olivia Bellantoni

which one of the following would be least likely to diffuse across a lipid bilayer?
A. H20
B. C6H12O6
C. CO2
D. N2
E. glycerol

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which of the following would most likely be a reactant in an anabolic reaction? 
A. an enzyme like PFK 1
B. a messenger RNA
C. an amino acid like tryptophan 
D. A and B
E. A B and C

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which one of the following is not an example of potential energy?
A. an electrochemical gradient
B. the chemical bonds in glucose
C. the chemical bonds in the fatty acid tail of a lipid
D. electrons in an outer shell
E. all of the above are examples of potential energy

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which one of the following statements about synthesizing a strand of DNA from free nucleotides is incorrect?
A. the reaction is non-sponanteous
B. the reaction is endergonic
C. the reaction is part of anabolism
D. the reaction has a negative delta G
E. all of the statements about synthesizing a strand of DNA from free nucleotides are incorrect

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which of the following reaction is most likely to be exergonic?
A. the eysnthesis of a strand of DNA from nucleotides
B. the synthesis of a protein from amino acids
C. the conversion of pyruvate to acetyl Co A
D. A and B
E. none of these reactions are exergonic

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what is the purpose of an enzyme?
A. to slow the rate of a reaction
B. to increase the energy required to reach the transition state
C. to alter the potential energy of a specific reaction
D. to increase the rate of a specific reaction by decreasing the energy required to reach the transition state
E. all of the above

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which of the following types of inhibitor temporarily alters the enzyme it inhibits, primarily by forming a transient bond in the active site of the enzyme?
A. a non-competitive inhibitor
b. a competitive inhibitor
C. an irreversible inhibior
D. an allosteric inhibitor
E. all of these inhibitors act in this way

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A selectively permeable membrane divides a container in half. Side A is filled with an iodine tincture, which is brown in color. Side B is filled with a colorless starch solution. Iodide ions turn dark blue when they react with starch molecules. After several hours, Side A is blue and Side B remains colorless. Which statement describes the diffusion of solutes through the membrane?
A.the membrane excluded the iodide ions, but the starch molecules diffused through
B. the membrane excluded the starch molecules, but the iodide ions diffused through
C. both the starch molecules and the iodide ions diffused through the membrane
D. the membrane excluded both the starch molecules and the iodide ions
E. none of the above

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which of the following is a property of facilitated diffusion though a membrane bound protein?
A. ions’ solutes are pumped from an area of low concentration to high concentration
B. cells must spend energy (ATP) to diffuse the ions/ solutes across the membrane
C. cells form a vesicle to diffuse substances across the membrane without using energy
D. ions/solutes are pumped along their ocncentration gradient (high to low) through a protein channel, requiring energy
E. diffusion occurs through a protein channel that only allows that type of ion/ solute to pass

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which of these summarizes the overall reaction of respiration?
A. C6H12O6 + 6O2 -> ^CO2 + 6H2O + energy
B. 6CO2 + 6O2 -> C6H12O6 + 6H20
C. C6H12O6 + 6O2 + energy -> 6CO2 + 12 H2O
D. 6CO2 + 6H2O + energy -> C6H12O6 + 6O2
E. H2O -> 2H+ + 1/2 O2 + 2e-

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carbon dioxide is a waste product of the complete oxidation of glucose. carbons dioxide ____.
A. is produced during glycolysis, pyruvate oxidation, and the citric acid cycle
B. is produced during acetyl Co A synthesis and in the electron transport chain
C. is produced when carbon is oxidized
D. is used as the final electron acceptor in the ETC
E. is produced when carbon is reduced

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which of the following would entirely disrupt the ability of ATP synthase to function in the mitochondrion?
A. sudden change in the permeability of the outer membrane allowing protons to freely flow across it
B. sudden decrease in the availability of FADH2
C. increased rate of glycolysis
D. sudden change in the permeability of the inner membrane allowing H2O to freely flow across it
E. increase efficiency of the enzyme PFK1

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Multicellular organisms have many types of cells that fulfill specialized roles. different cell types can vary in the numbers of certain organelles that they contain. compare the density of mitochondria in cardiac muscle cells to the density in skin cells. what relationship do you expect>
A. cardiac cells need a higher density of mitochondria because they are required to beat and need to produce more ATP to do so.
B. the number and density of mitochondria is the same for both cell types
C. skin cells have a higher rate of metabolism because of their increased surface area and need a higher density of mitochondria
D. there is no relationship

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Cellular respiration requires oxygen and releases energy. which of the following statements most accurately summarizes cellular respiration:
A. chemical potential energy in organic macromolecules is released in a series of enzymatic reactions that convert it into an energy currency molecule
B. chemical potential energy in the bonds of organic macromolecules is transferred to chemical potential energy in the bonds of ATP
C. the chemical potential energy stored in organic molecules is converted to chemical energy that can be used to do the work of the cell
D. all of the above accurately summarize cellular respiration
E. none of the above

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Complete oxidation of glucose to CO2 involves two different mechanism for synthesizing ATP, oxidative phosphorylation and substrate level phosphorylation. which statement is true?
A. in substrate level phosphorylation an enzyme catalyzes the addition of a phosphate group to ADP to form ATP
B. most of the ATP generated is due to oxidative phosphorylation
C. in substrate level phosphorylation the substrate released more than 7 kcal/mol when the phosphate group is transferred from it.
D. oxidative phosphorylation requires a proton gradient
E. all of the above

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which one of the following is the set of complexes that pump protons in the mitochondrion?
A. Complex I, II, III
B. Complex I, III,IV
C. Complex II, III, IV
D. Complex III, IV
E. Complex I,II, III, IV

The pyruvate from glycolysis is concerted into acetyl Coa which enters the citric acid cycle. Because the process is a cycle, the atoms entering the cycle must balance the atoms that leave. Consider carbon balance in the CAC. how many CO2 molecules leave the cycle for each pyruvate that enters it?
A. 1
B. 2 
C. 3
D. 4
E. 5

How many molecules of CO2 would be generated during the CAC from 3 molecules of acetyl CoA? 
A. 2 
B. 4
C. 6
D.8 
E. 10

imagine a cell receives a signal to grow and divide, which requires energy. as a result the cell begins to use available ATP to power the assembly of macromolecules. how will these events affect the regulation of respiration?
A. ADP levels will increase and will decrease the speed of the enzyme PFK1
B. App levels will decrease and ATP will bind to PFK 1 increasing its speed
C. citrate levels will increase and its accumulation will increase the speed of the enzyme PFK1
D. citrate will decrease, decreasing the speed of PFK1
E. ADP levels will increase and it will bind to PFK 1 increasing its speed

You want to determine the composition of the membrane of a bacteria that live in hot springs. You compare your bacteria with one that lives at room temperature and has a membrane composition as follows: 20% saturated fatty acids, 30% unsaturated fatty acids, 5% cholesterol, 45% protein. which of the following best represents the data you expect to collect for the hot springs bacteria?
A. 10%, 40%, 10%, 40%
B. 30%, 30%, 10%, 30%
C. 5%, 55%, 15%, 25%
D. 55%, 10%, 15%, 20%
E. 55%, 20%, 5%, 20%

Imagine that a cell has completely run out of glucose. What impact will this have on the CAC?
A. Concentrations of acetyl CoA entering the CAC will increase
B. Concentrations of CO2 will immediately increase
C. the cell will begin to produce ATP via fermentation
D. the cells production of ATP via oxidative phosphorylation will be unaffected
E. concentrations of oxaloacetate will go up, while concentrations of citrate begin to go down.

Some ribosomes are used to make proteins such as insulin that are modified and sent out of the cell. Where in the cell does the ribosome complete the translation of the mRNA for insulin?
A. SER
B. RER
C. cytosol
D. Nucleus
E. all of the above

The adrenal glands are the site of synthesis of steroid hormones. As a result, these cells produce and secrete a large quantity of these hormones, which are modified forms of cholesterol, a type of lipid. Which of the following features would you expect to find in cells of the adrenal glands?
A. they would have an expanded nucleus with extra copies of the genes encoding cholesterol
B. they would contain large quantities of SER
C. they would have large quantities of RER
D. they would contain a large number of lysosomes
E. they would have two to three times as many mitochondria as other cells.

You are a cell biologist working cancer cell signaling. You discover a protein that when exported by one cell and taken up by adjacent cells, turns healthy cells into cancer cells. In normal healthy cells this same protein is located in the outer membrane of the cell. Which of the following hypotheses would you test?
A. the gene encoding the protein has a mutated promotor in the cancer cells that leads to the overproduction of the protein
B. the targeting peptide in the cancer cells is at the C-terminus of the protein, but the N-terminus of the healthy cells.
C. IN cancer cells, a mutation in the DNA results in a new signal sequence that is recognized by a signal recognition particle
D. the cancer cells have mutated nuclear pores that allow mRNAs that should not leave the nucleus to do so.
E. in cancer cells, a mutation results in the loss of the signal anchor sequence of the encoded protein

``` Some diseases such as Tay-Sachs, are caused by the defective breakdown of cellular components. Which of the following organelles is defective? A. nucleus B. golgi apparatus C. ribosome D. endoplasmic reticulum E. none of the above ```

The electrical component of an electrochemical gradient is due to: A. a greater concentration of positive charges on the side of the membrane with the lowest concentration of protons B. a higher concentration of negative charges on the side for the membrane with the highest concentration of protons C. a greater concentration of positive charges on the side of the membrane with the highest concentration of protons D. a lower concentration of negative charges on the side of the membrane with the lowest concentration of protons

``` the sodium/potassium pump is an example of: A. a symporter B. passive transport C. an antiporter D. channel mediated diffusion E. none of the above ```

An unsaturated fatty acid contains: A. only carbon and hydrogen B. only single covalent bonds between carbon atoms C. one or more double bonds between carbon atoms D. one or more double bonds between hydrogen atoms E. both double bonds between carbon atoms and double bonds between carbon and hydrogen

``` RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through: A. nuclear pore complexes B. sodium potassium chanelles C. passive diffusion D. budding off of the nuclear envelope E. aquaporins ```

Many hydrophilic molecules interact freely with water, but there are a number of hydrophobic molecules important for life, too. How does the interaction between water and hydrophobic molecules help to organize biological systems? A. the covalent bonds between water molecules cause hydrophobias molecules to associate with one another and not with water molecules B. because cells are not pure water, the hydrophilic/hydrophobic effect has little role on biological organization C. because water molecules preferentially associate with one another, they force hydrophobias molecules to associate with one another and not with water molecules D. all of the above E. none of the above

the laws of thermodynamics explain why: A. cells are not perfectly efficient at extracting energy from reactions they perform, some formerly usable energy lost to entropy in the form of heat B. the amount of disorder decreases after each energy transformation C. absolute temperature is the most important factor in energy transformation in cells D. cells primarily use energy from other cells to survive E.None of these are true

``` Simple diffusion requires: A. a concentration gradeint B. a plama membrane C. a transport protein D. A and B E. A,B, and C ```

``` Which component of a phospholipid would most likely be found exterior of a lipid bilayer? A. glycerol B. phosphate C. fatty acids D. both B an C E. A B and C ```

Which of the following reactions would you predict could be coupled to ATP synthesis from ADP +Pi to make it energetically favorable, or spontaneous? A. creatine + Pi = creatine phosphate + H2O DeltaG + 10.3 kcal/mol B.glutamic acid + NH3 = glutamine, deltaG +3.4 kcal/mol C. glucose 1-phosphate + H2O = glucose + Pi, DeltaG -3.3 kcal/mol D. glucose 1-phosphate + H2O = glucose + Pi, DeltaG -5.0 kcal/mol E. phosphoenolpyruvate + H2O = pyruvate + Pi, DeltaG -14.8 kcal/mol

``` Which of the following complexes acts to reduce O2 to H2O? A. complex I B. Complex II C. Complex III D. Complex IV E. None of the above ```

``` When NAD+ is converted to NADH it is ___; When FADH2 is converted to FAD it is___. Of these four molecules, ____ stores the most energy for use in oxidative phosphorylation. A. reduced; oxidized; FADH2 B. oxidized; reduced; NADH C. reduced; oxidized; NADH D. oxidized; reduced; FADH2 E. none of the above ```

What are the reactant and products during the conversion of the 3 carbon molecule produced by glycolysis to the 2 carbon molecule required by the CAC? A.reactants: acetyl coA, NAD+, ADP, Pi,FAD, H2O; products: CO2, NADH, FADH2, ATP B. Reactants: glucose, ADP, NAD+, Pi Products: pyruvate, H2O, ATP, NADH C. Reactants: pyruvate, NAD+, coenzyme A Products: NADH, CO2, Acetyl CoA D. Reactants: pyruvate, NADH, Pi Products: acetyl CoA, NAD+, CO2 E. none of the above

When carbohydrates are oxidized the C-H bonds of the carbohydrate become C-O bonds of carbon dioxide. Oxidation is defined as a loss of electrons, but carbon does not become positively charged in this process. Why then is this considered carbon oxidation? A. the shared electrons in C-O bonds spend less time close to the carbon nucleus than shared electrons in the C-H bonds B> electrons in the C-O bonds are higher energy than the electrons in the C-H bonds C. C-O bonds in CO2 are double bonds, and C-H bonds are single bonds D. the phosphate groups of ATP are ionized, and carbons donate those electrons E. both A and B