Biology 212 Exam 2
According to the second law of thermodynamics, which of the following statements is INCORRECT? a. The synthesis of large molecules from small molecules is exergonic (releases free energy). b. Living organisms cannot be closed system. c. Life exists at the expense of energy derived from its environment. d. A living cell can never function indefinitely as a closed system. e. Every chemical reaction in a cell results in a loss of free energy
A
During aerobic cellular respiration, a proton gradient in mitochondria is generated by ________ and used primarily for ________. a. the electron transport chain; ATP synthesis b. the electron transport chain; substrate-level phosphorylation c. glycolysis; production of H2O d. fermentation; NAD+ reduction
A
Each of the following can be converted to an intermediate of glycolysis and produce some ATP without entering the citric acid cycle EXCEPT a. fatty acids b. some amino acids c. glucose and sucrose d. glycerol e. starch and glycogen
A
How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate, and eventually emerge as CO2? a. 2 b. 4 c. 6 d. 8
A
If all of the molecules of an enzyme are saturated with substrate, the most effective way to obtain a faster yield of products (increase the reaction rate) is to a. add more of the enzyme. b. heat the solution to 90°C. c. add more substrate. d. add an allosteric inhibitor.
A
In fermentation by yeast, NAD+ is regenerated from NADH during the a. conversion of pyruvate to ethanol (ethyl alcohol). b. conversion of pyruvate to acetyl CoA. c. conversion of pyruvate to lactate. d. phosphorylation of ADP to form ATP.
A
Shutdown of an early step in a metabolic pathway by an end product of that pathway is best described, without any additional information, as a. feedback inhibition. b. allosteric inhibition. c. noncooperative inhibition. d. competitive inhibition.
A
The ATP made during glycolysis is generated by a. transfer of phosphate from a phosphorylated carbon molecule to ADP, called substrate-level phosphorylation. b. electron transport. c. chemiosmosis. d. oxidation of NADH to NAD+
A
The ATPs generated during glycolysis are formed by which mechanism, substratelevel phosphorylation or oxidative phosphorylation? a. Substrate-level b. Oxidative phosphorylation
A
The manufacture of a large protein from hundreds of amino acids is likely to a. require energy input b. release energy that can potentially be used for other purposes c. result in no change in free energy d. be exergonic, with a large negative ΔG
A
What are the repeating DNA sequences at the ends of chromosomes that protect them from loss of important DNA during replication? a. Telomeres b. Telomerase c. Replicons d. Primers e. Promoters
A
What is the function of helicase during DNA replication? a. It separates the two strands of the double helix. b. It relieves the overwinding of DNA ahead of the replication fork due to DNA strand separation. c. It synthesizes the RNA primers used to initiate DNA replication. d. It joins the Okazaki fragments together.
A
What is the term that best describes the metabolic pathway in which glucose (C6H12O6) is degraded to carbon dioxide (CO2) and water? a. cellular respiration b. glycolysis c. fermentation d. citric acid cycle e. oxidative phosphorylation
A
When oxygen is in short supply, your muscle cells convert pyruvate produced by glycolysis to ________, and in this step gain ________. a. lactate; NAD+ which permits glycolysis to continue. b. alcohol; CO2 c. alcohol; ATP d. ATP; NADH2
A
Where does the Calvin cycle take place? a. stroma of the chloroplast b. thylakoid membrane c. cytoplasm surrounding the chloroplast d. chlorophyll molecule e. outer membrane of the chloroplast
A
Which of the following normally occurs in your cells regardless of whether or not oxygen (O2) is present? a. glycolysis b. fermentation c. conversion of pyruvate to lactate d. citric acid cycle e. oxidative phosphorylation (chemiosmosis)
A
Which statement about the formation of water by the mitochondrial electron transport chain is TRUE? a. The electrons come from carbohydrates and the oxygen come from O2. b. The ∆G is positive. c. Energy from ATP is required to make the reactions occur. d. Cytochromes do not play any role in the process.
A
Which steps in the metabolic pathway of cellular respiration occur in the cytosol? a. glycolysis b. pyruvate break down c. citric acid cycle d. oxidative phosphorilation e. all but d f. a & b g. none of the above
A
A drug is designed to make the glycolytic pathway more productive. What part of the cell would the drug need to be delivered to for it to directly affect this pathway? a. mitochondrial matrix b. cytosol/cytoplasm c. mitochondrial intermembrane space d. nucleus e. chloroplast
B
Anaerobic fermentation adds reactions to glycolysis in which ________ is ________. a. NAD+; oxidized to NADH b. NADH; oxidized to NAD+ c. pyruvate; converted to acetylCoA d. ethanol; oxidized
B
As ATP levels in the cytoplasm of a cell increase, the rate of glycolysis is likely to a. go up, because more ATP is available for the energy investment phase of glycolysis. b. go down, because elevated ATP results in feedback inhibition of phosphoglucokinase. c. remain unchanged, because the rate of glycolysis is controlled by the availability of oxygen. d. slow, because NAD+ is used up
B
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? a. glycolysis and the oxidation of pyruvate to acetyl CoA b. oxidation of pyruvate to acetyl CoA and the citric acid cycle c. the citric acid cycle and oxidative phosphorylation d. oxidative phosphorylation and fermentation e. fermentation and glycolysis
B
Eukaryotic chromosomes have telomeres that protect the terminal nucleotides from degradation by nucleases. Bacterial chromosomes do not need telomeres because a. bacterial DNA replication has no lagging strand synthesis, so there is no overhang to protect. b. bacterial chromosomes are circular. c. bacteria have specialized proteins that protect the ends of their chromosomes. d. bacterial DNA polymerases can synthesize DNA bidirectionally. e. bacterial chromosomes have a single origin of replication at one end of each linear chromosome.
B
Growing organisms increase in complexity, so their entropy must decrease. The only way to reconcile this with the second law of thermodynamics is to realize that a. Living organisms do not obey the second law of thermodynamics, which states that disorder (entropy) must increase with time. b. Living things are not closed systems -they extract free energy from their surroundings to do biological work necessary to maintain and increase order, the entropy of the total system in which they live still increases. c. Living organisms can create new free energy via photosynthesis, and use that energy to decrease their own entropy. d. Enzyme catalysts reduce the activation energy for the conversion of entropy back into free energy.
B
How are telomeres made? a. By ligation of adjacent Okazaki fragments. b. Telomerase synthesizes them by copying the telomerase RNA. c. By telomerase which is capable of synthesizing DNA in the 3' to 5' direction. d. By fusion of adjacent replicons.
B
In exergonic reactions, like the oxidation of glucose, a. the end products have more total energy than the starting reactants. b. there is a net release of free energy. c. a net input of energy from the surroundings must occur. d. the reaction cannot proceed without enzymes that lower the activation energy.
B
In your body, the most important function of ribonucleic acid (RNA) is to a. transmit genetic information to offspring. b. direct the synthesis of protein. c. serve as a template for the synthesis of a complementary copy, thus ensuring genetic continuity. d. act as a template directing the synthesis of DNA.
B
Living organisms increase in complexity as they grow, resulting in an apparent decrease in their entropy. How does this relate to the second law of thermodynamics? a. Living organisms do not obey the second law of thermodynamics, which states that disorder (entropy) must increase with time. b. Life obeys the second law of thermodynamics because living things are not closed systems - though they become more complex (ordered), they extract free energy from their surroundings to do that, and increase the entropy of their surroundings. c. Living organisms can create new free energy via photosynthesis, and use that energy to decrease their own entropy. d. Enzyme catalysts reduce the activation energy for the conversion of entropy back into free energy.
B
Most of the ATP made during cellular respiration is produced by a. glycolysis. b. oxidative phosphorylation. c. substrate level phosphorylations. d. direct synthesis of ATP by the tricarboxylic acid cycle.
B
The citric acid cycle is a "cycle" because: a. CO2 is released at various steps in the cycle and then fixed again. b. oxaloacetate is regenerated in each round of the cycle. c. ATP is hydrolyzed, then resynthesized. d. All of the above. e. None of the above
B
The mathematical expression for the change in free energy of a system is: ∆G = ∆H - T∆S. Which of the following is NOT CORRECT for this expression? a. ∆G is the change in free energy. b. ∆H, the change in enthalpy, is defined as the energy available to do work. c. ∆S is the change in entropy, a measure of randomness. d. T is the absolute temperature measured in Kelvins.
B
The most important function of long-chain polypeptides in organisms is in a. storage of chemical potential energy for later use. b. catalysis that speeds up the rate of important biochemical reactions. c. coding of genetic information in a form that can be duplicated and partitioned when cells divide. d. All of the above are important functions of long-chain polypeptides.
B
The oxygen consumed during cellular respiration is involved directly in which process or event? a. glycolysis b. accepting electrons (and H+) at the end of the electron transport chain, forming water c. the citric acid cycle d. the oxidation of pyruvate to acetyl CoA e. the phosphorylation of ADP to form ATP
B
The primary role of molecular oxygen (O2) in cellular respiration is to a. yield energy in the form of ATP as it is passed down the respiratory chain. b. act as an acceptor for electrons and hydrogen, forming water. c. combine with carbon, forming CO2. d. react with pyruvate to form lactate or ethanol, regenerating NAD+.
B
The purine bases in DNA are? a. Cytosine, thymine and uracil b. Adenine and guanine c. Cytosine and thymine d. Thymine, guanine and cytosine e. Adenine, uracil and guanine
B
The structural feature that allows near-perfect copying of DNA molecules is a. their sugar-phosphate backbone. b. the capability of its nitrogenous bases to form specific hydrogen bonds that lead to matching of specific pairs of nucleotides. c. disulfide bonds that hold the two helixes together. d. the three-component (base, sugar, and phosphate) structure of the nucleotides, because all three must be matched to make a perfect copy.
B
Trans-fats are are a. rich in cholesterol b. unsaturated, and contain one or more double bonds. c. saturated, and more abundant in plant oils than in fish oils. d. phospholipids, with both polar and non-polar regions.
B
We measure energy in the units of ______________________, and power in units of ________________. a. joules or watts, calories or kilocalories b. joules or calories, watts or calories/day c. Gibbs free energy, entropy d. ATP, NADH
B
What is the function of topoisomerase during DNA replication? a. It separates the two strands of the double helix. b. It relieves the overwinding of DNA ahead of the replication fork due to DNA strand separation. c. It synthesizes the RNA primers used to initiate DNA replication. d. It joins the Okazaki fragments together.
B
When Hershey/Chase performed phage infection experiments, what compounds did they use to label and detect DNA and protein? a. 35S was used to label DNA, and 32P was used to label protein. b. 35S was used to label protein, and 32P was used to label DNA.
B
Which of the following is true for all exergonic reactions? a. The products have more total energy than the reactants. b. There is a net release of free energy. c. A net input of energy from the surroundings is required for the reactions to proceed. d. The reactions are nonspontaneous.
B
Which of the following statements about NAD+ is FALSE? a. NAD+ is reduced to NADH during both glycolysis and the citric acid cycle. b. NAD+ has more chemical potential energy than NADH. c. NAD+ can receive electrons for use in electron transport and oxidative phosphorylation. d. In the absence of NAD+, glycolysis cannot proceed.
B
Which of the following statements about enzymes is FALSE? a. Enzyme catalysis is dependent on the three-dimensional structure or conformation of the enzyme. b. Enzymes provide activation energy for the reaction they catalyze. c. Enzymes are composed primarily of protein, but they may bind nonprotein cofactors. d. Enzyme activity can be inhibited by other molecules, even if they do not bind to the active site.
B
Which of the following statements is correct with respect to anabolic pathways? a. They do not depend on enzymes. b. They consume energy to build up polymers from monomers. c. They release energy as they degrade polymers to monomers. d. They result in net production of ATP.
B
Which type of inhibitor binds to the active site of an enzyme? a. allosteric inhibitor b. competitive inhibitor c. non-competitive inhibitor d. feedback inhibitor
B
Why is ATP an important molecule in metabolism? a. Its hydrolysis provides an input of free energy for exergonic reactions. b. It provides energy coupling between exergonic and endergonic reactions. c. Its terminal phosphate group is highly unstable, and thus reactive. d. A and B are both correct
B
A chemical reaction occurs spontaneously with the release of energy. Which of the following must be true for that reaction? a. ∆G > 0 b. ∆G = 0 c. ∆G < 0 d. T∆S < 0
C
A drug that increases the number of NADH & FADH2 molecules produced through the citric acid cycle/Krebs cycle and has no other effects on the cell would theoretically a. decrease the activity of ATP synthase. b. decrease the cell's ability to manufacture glycerol. c. increase the number of ATPs produced per glucose. d. increase lactic acid production. e. decrease the cell's need for oxygen
C
A reaction will proceed spontaneously when: a. The products of the reaction have more free energy than the reactants, therefore the ΔG < 0. b. The products of the reaction have more free energy than the reactants, therefore the ΔG > 0. c. The products of the reaction have less free energy than the reactants, therefore the ΔG < 0. d. The products of the reaction have less free energy than the reactants, therefore the ΔG > 0. e. The products of the reaction have the same amount of free energy as the reactants, therefore the ΔG = 0.
C
A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because a. the starch solution has less free energy than the sugar solution. b. the hydrolysis of starch to sugar is endergonic. c. the activation energy barrier is too high for the reaction to go very fast at room temperature. d. starch cannot be hydrolyzed in the presence of water.
C
ATP generally energizes cellular processes by which of the following? a. releasing heat upon hydrolysis b. acting as a catalyst c. direct chemical transfer of a phosphate group d. releasing ribose electrons to drive reactions
C
ATP is produced by _______ , ________ reactions and is used to drive ________, ________ reactions. What words filled in these four spaces (in order) result in a true statement? a. endergonic, catabolic exergonic, anabolic b. exergonic, anabolic endergonic, catabolic, c. exergonic, catabolic endergonic, anabolic d. endergonic, anabolic exergonic, catabolic
C
An enzyme whose regulation by a variety of other molecules is important in controlling the rate of glycolysis in a cell is a. coenzyme A b. pyruvate carboxylase c. phosphofructokinase d. isomerase
C
Citric acid cycle intermediates, like oxaloacetate, alpha ketogluterate, succinate, fumerate, and malate a. carry electrons in the electron transport chain that ends in the conversion of O2 to H2O. b. are specialized molecules that are useful only in the citric acid cycle, because removing them would break the cycle. c. are important as building materials for other organic molecules, in addition to their role in the citric acid cycle. d. are converted to pyruvate at the end of the citric acid cycle reaction sequence.
C
During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is a. transferred to ADP, forming ATP. b. transferred directly to ATP. c. retained in the pyruvate. d. stored in the NADH produced.
C
Hemoglobin is a tetramer, composed of four polypeptide subunits. When one of the subunits binds an oxygen molecule, the affinity for oxygen of other subunits increases, so additional oxygen uptake becomes more likely. This is best described as the result of: a. enzyme saturation b. allosteric inhibition c. allosteric activation d. oxidative damage
C
Hydrogen bonding between nitrogenous bases is essential for correct replication of DNA. Which of the following base pairs forms two hydrogen bonds in DNA? a. Adenine - Guanine b. Adenine - Cytosine c. Adenine - Thymine d. Adenine - Adenine
C
In addition to ATP, other end products of glycolysis include: a. CO2 and H2O b. CO2 and pyruvate c. NADH and pyruvate d. CO2 and NADH
C
Photosystem II strips electrons from chlorophyll and delivers them to the chloroplast electron transport (cytochrome) chain. Where do the replacement electrons come from? a. splitting O2 b. photosystem I c. splitting H2O d. splitting CO2 e. NADPH
C
The pyrimidine bases in DNA are— a. Cytosine, thymine and uracil b. Adenine and guanine c. Cytosine and thymine d. Thymine, guanine and cytosine e. Adenine, uracil and guanine
C
The two strands making up the DNA double helix molecule a. cannot be separated. b. contain ribose and deoxyribose in opposite strands. c. are held together by hydrogen bonds. d. are attached via ester bonds between phosphates that hold the strands together.
C
What is the function of primase during DNA replication? a. It separates the two strands of the double helix. b. It relieves the overwinding of DNA ahead of the replication fork due to DNA strand separation. c. It synthesizes the RNA primers used to initiate DNA replication. d. It joins the Okazaki fragments together.
C
What key component is necessary for photosystems to harvest light? a. vesicles b. NADP reductase c. pigment molecules d. ATP synthase e. Calvin cycle
C
What molecule is produced by glycolysis, and is then imported into the mitochondria to enter into the TCA cycle? a. glucose b. NADPH c. pyruvate d. citric acid
C
Where are the proteins of the respiratory electron transport chain located? a. cytosol b. mitochondrial outer membrane c. mitochondrial inner membrane d. mitochondrial intermembrane space e. mitochondrial matrix
C
Where do the catabolic products of fatty acid breakdown enter into the citric acid cycle? a. pyruvate b. malate or fumarate c. acetyl CoA d. alpha-ketoglutarate e. succinyl CoA
C
Which of the following is FALSE? a. Enzyme catalysis is dependent on the pH and temperature of the reaction environment. b. Enzyme catalysis is dependent on the three-dimensional structure or conformation of the enzyme. c. Enzymes provide activation energy for the reaction they catalyze. d. Enzyme activity can be inhibited by a molecule that binds to the enzyme far from the active site.
C
Which of the following is most similar in structure to ATP? a. a steroid, like cholesterol b. a DNA double helix c. a nucleotide d. an amino acid with three phosphate groups attached e. a phospholipid
C
Which of the following is the best description of the class of molecules known as nucleotides? a. a nitrogenous base linked to a phosphate group b. a nitrogenous base linked to a pentose (5 carbon) sugar c. a molecule including a nitrogenous base, a pentose (5 carbon) sugar and a phosphate group d. a phosphate group linked to an adenine or uracil e. a pentose sugar linked to a purine or pyrimidine
C
Which of the following statements about DNA replication is NOT correct? a. Leading strand synthesis is continuous, while lagging strand synthesis is discontinuous. b. Both leading and lagging strands are synthesized in the 5' to 3' direction. c. Leading strand synthesis is conservative, while lagging strand synthesis is semi-conservative. d. Completion of the lagging strand requires ligation of Okazaki fragments
C
Which of the following statements about the chemiosmotic mechanism of ATP synthesis is TRUE? a. electron transport from NADH to O2 pumps H+ from the intermembrane space into the mitochondrial matrix. b. The high concentration of H+ in the mitochondrial matrix pulls water into the matrix through the ATP synthase channel by osmosis, and the energy in this water flow is used to power ATP synthesis. c. H+ movement down a concentration gradient from the intermembrane space into the mitochondrial matrix through ATP synthase results in ATP synthesis d. All these statements describe parts of the chemiosmotic mechanism.
C
Which of the following statements correctly describe(s) catabolic pathways? a. They do not depend on enzymes. b. They consume energy to build up polymers from monomers. c. They release energy as they break down organic molecules. d. both A and B are correct
C
You are studying the biochemistry of muscle cell samples from worldclass sprinters, and isolate a compound that is highly soluble in water, and varies in molecular weight, but averages about C60H100O50. Cells without this substance run out of ATP very quickly when oxygen is absent, but work for longer periods if this substance is present. The substance is most likely to be a a. Lipid b. Protein c. Carbohydrate d. Nucleic acid e. Enzyme
C
A change in an enzyme's three-dimensional shape and disruption of normal function, due to alteration of hydrogen bonds or ionic bonds caused by an increase in temperature, is best labeled: a. hydrolysis b. destabilization c. allosteric inhibition d. denaturation
D
A major function of the mitochondrial inner membrane is the conversion of energy from electrons to the stored energy of the phosphate bond in ATP. To accomplish this function, the inner mitochondrial membrane must have all of the following features EXCEPT a. carrier proteins to accept electrons from NADH. b. ATP synthase as an integral protein spanning the width of the membrane. c. the electron transport chain of proteins. d. high permeability to protons (H+ ions).
D
A proton ionophore is a substance that creates a proton leak in a membrane. What might you predict that a proton ionophore would do in mitochondria? a. Nothing. b. Create a greater proton motive force. c. Block electrons from being transported from one carrier to another. d. Prevent the synthesis of ATP. e. None of the above.
D
A substance that increases the number of protons (H+) in the mitochondrial matrix (and has no other effect on the cell) would theoretically ____. a. increase the ATP yield of glycolysis b. decrease ATP yield in the citric acid cycle/Krebs cycle c. inhibit pyruvate metabolism d. decrease the ATP yield in oxidative phosphorylation e. increase the ATP yield of fermentation
D
Enzymes speed the rate of substrate conversion to product by which of the following mechanisms? a. increasing the energy of the substrate b. decreasing the energy of the product c. decreasing the ∆G of the reaction d. decreasing the activation energy of the reaction
D
How could you tell whether or not a particular reaction you were studying was enzyme-catalyzed? a. Remove proteins from the reaction mixture and see what happened to the reaction rate. b. Try different concentrations of the reactants to see if the reaction rate first increased with reactant concentration, then stopped changing even though reactant concentration was further increased. c. Measure the activation energy. d. A and B would both provide useful information, but C would not.
D
In the double helix structure of nucleic acids, cytosine hydrogen-bonds to a. deoxyribose. b. adenine. c. thymine. d. guanine.
D
Phosphofructokinase is a protein that catalyzes a reaction that controls the rate of glycolysis in animal cells. The term kinase means that this protein a. breaks a large molecule down to smaller parts (catabolism) b. catalyzes a reaction that produces ATP c. can be allosterically activated by molecules that bind to regions away from its active site. d. adds a phosphate group to or removes a phosphate group from another molecule.
D
The second law of thermodynamics is consistent with each of the following statements EXCEPT: a. Conversion of energy from one form to another always results in some loss of free energy. b. Without occasional input of energy, organisms would tend to fall apart. c. Cells must use energy continually to maintain their high level of organization. d. Every energy transformation by a cell increases the order and decreases the entropy of the universe.
D
What is the function of ligase during DNA replication? a. It separates the two strands of the double helix. b. It relieves the overwinding of DNA ahead of the replication fork due to DNA strand separation. c. It synthesizes the RNA primers used to initiate DNA replication. d. It joins the Okazaki fragments together.
D
Where does glycolysis takes place? a. mitochondrial outer membrane b. mitochondrial inner membrane c. mitochondrial intermembrane space d. cytosol (the cytoplasm of the cell)
D
Where is the chlorophyll located in a plant? a. Cristae b. Plasma membrane of the cell c. Outer membrane of the chloroplast d. Thylakoid membrane e. Stroma
D
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? a. glucose-6-phosphate b. glyceraldehyde-3-phosphate c. oxaloacetate d. acetyl CoA
D
Which of the following is NOT a result of the citric acid cycle? a. Oxidation of pyruvate to CO2 b. Reduction of NAD+ to NADH c. Production of ATP through substrate level phosphorylation d. Partial oxidation of glucose in the absence of oxygen to produce ATP at low rates during anaerobic conditions.
D
Which of the following statements concerning the metabolic degradation of glucose (C6H12O6) to carbon dioxide (CO2) and water is (are) true? a. The breakdown of glucose to carbon dioxide and water is exergonic, releasing free energy. b. The breakdown of glucose to carbon dioxide and water in a cell is usually coupled to the production of more than 25 ATP. c. The breakdown of glucose to carbon dioxide and water is completed in the reactions of the citric acid cycle in the mitochondrial matrix. d. All of the above are true.
D
Which of the following statements regarding ATP is (are) correct? a. ATP serves as a main energy shuttle inside cells. b. ATP drives endergonic reactions in the cell by transfer of the phosphate group to specific reactants. c. The regeneration of ATP from ADP and phosphate is an endergonic reaction, requiring energy input. d. All of the above are correct.
D
Which statement is NOT TRUE about glycolysis? If all are true, select alternative D. a. Two ATP are needed per glucose in the energy investment phase of glycolysis b. Four ATP per glucose are produced during the energy yielding phase of glycolysis c. The two NADH produced per glucose can be oxidized back to NAD+ by the mitochondrial electron transport chain. d. All of the above are true.
D
All of the following are products of the citric acid cycle EXCEPT a. ATP. b. NADH. c. FADH2. d. carbon dioxide. e. water
E
If an enzyme is added to a solution where the substrates and products are in equilibrium, what would occur? a. Additional product would be formed. b. Additional substrate would be formed. c. The reaction would change from endergonic to exergonic. d. The free energy of the system would change. e. Nothing; the reaction would stay at equilibrium.
E
In a plant cell, where are the ATP synthetase complexes located? a. A. stroma of the chloroplast b. B. thylakoid membrane c. C. outer membrane of the chloroplast d. D. inner membrane of the mitochondria e. choices B and D are both correct
E
Which of the following are CORRECT statements about enzymes? a. Enzymes may require a nonprotein cofactor or metal atom for catalysis to take place. b. An enzyme's catalytic rate is likely to change if its threedimensional structure is altered. c. Enzyme activity is influenced by physical and chemical environmental factors such as pH and temperature. d. Enzymes increase the rate of chemical reaction by lowering activation energy barriers. e. All of the above are correct.
E
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? a. CO2 and glucose b. H2O and O2 c. ADP, Pi, and NADP+ d. electrons and H+ e. ATP and NADPH
E
Which of the following are true about photorespiration? a. A. It is an apparently wasteful side reaction of ribulose bisphosphate carboxylase (Rubisco). b. B. It is a useful supplement to cellular respiration. c. C. It is minimized in C4 plants due to specialized photosynthetic pathways and leaf architecture. d. All of the above. e. Choices A and C are both correct.
E
Which of the following produces the most ATP when a glucose molecule (C6H12O6) is oxidized to carbon dioxide (CO2) and water? a. glycolysis b. fermentation c. oxidation of pyruvate to acetyl CoA d. the citric acid cycle e. oxidative phosphorylation (electron transport and chemiosmosis)
E
Which of the following statements about nucleosomes are correct? a. Contain about 150 bp of DNA wrapped around histones b. The histones are called H1, H2A, H3 and H4 c. The histones are basic proteins which is important to bind DNA d. Nucleosomes represent the first level of compaction of the eukaryotic chromosome e. All of the above
E
Which statement about the subcellular localization of the respiratory pathways is FALSE? If they are all true choose E. a. Glycolysis reactions are located in the cytosol (the cytoplasm of the cell). b. The citric acid cycle (also known as the Krebs cycle or tricarboxylic acid cycle) occurs within the mitochondrial matrix c. The electron transport chain and ATP synthase are located in the inner mitochondrial membrane d. Pyruvate must be transported from the cytosol to the mitochondrial matrix in oxidative respiration. e. All of the above are correct
E
A reaction will proceed spontaneously when - a. it is endergonic. b. It is exergonic
b
