Spring 2016 MC Questions
Which of the following is an enzyme? a. ribulose b. sucrose c. dehydrogenase d. NADH
c. (dehydrogenase)
Several prosthetic groups act as redox centers in Complex I, including: a. FMN, ubiquinone, iron-sulfur clusters, heme b. heme, ubuquinone, iron-sulfur clusters c. FMN, ubuquinone, iron-sulfur clusters d. all of the above e. none of the above
?? (maybe e)
Which of the following is MOST often associated with free fatty acid transport in human blood? A) Albumin B) Globulin C) Cholesterol D) Sphingolipid E) Mucopolysaccharide
A. (Albumin)
When the pentose pathway metabolizes glucose, the C-1 of glucose ends up mostly in: A) CO2 B) glycogen C) 3-phosophoglycerate D) pyruvate E) ribulose-5-phosphate
A. (CO2)
When the pentose pathway metabolizes glucose, the C-1 of glucose ends up mostly in: A) CO2 B) glycogen C) 3-phosophoglycerate D) pyruvate E) ribulose-5-phosphate
A. (CO2)
When undergoing strenuous anaerobic exercise the Cori Cycle is functioning. Which of the following compounds is being delivered to muscle tissue from the liver as part of this cycle? A. Glucose B. Lactate C. Galactose D. Pyruvate E. Alanine
A. (Glucose)
A metabolic pathway that is active catabolically as well as anabolically is called? A) amphibolic B) amphother C) bipartite D) departed E) bipolar
A. (amphibolic)
In the reoxidation of QH2 by purified ubiquinone-cytochrome c reductase (Complex III) from heart muscle, the overall stoichiometry of the reaction requires 2 mol of cytochrome c per mole of QH2 because: A. cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor. B. cytochrome c is a two-electron acceptor, whereas QH2 is a one-electron donor. C. cytochrome c is water soluble and operates between the inner and outer mitochondrial membranes D. heart muscle has a high rate of oxidative metabolism, and therefore requires twice as much cytochrome c as QH2 for electron transfer to proceed normally. E. two molecules of cytochrome c must first combine physically before they are catalytically active.
A. (cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor)
Inner mitochondrial membrane does not allow the free movement of one of the following compounds. A) O2 B) ATP C) CO2 D) H2O
B. (ATP)
An enzyme involved in the glycogen breakdown to glucose will be allosterically _______ in presence of excess ATP? A. Upregulated B. Downregulated C. Will have no effect D. ATP is not an allosteric regulator
B. (Downregulated)
Malonate is a competitive inhibitor of succinate dehydrogenase. If malonate is added to a mitochondrial preparation, which of the following compounds would you expect to decrease in concentration? A. Citrate B. Fumarate C. Isocitrate D. Pyruvate E. Succinate
B. (Fumarate)
Which is a reactant in the Krebs Cycle? A. CO2 B. acetyl-CoA C. NADPH D. FADH2
B. (acetyl-CoA)
Two hormones which act similarly to increase glycogen and lipid breakdown as well as cyclic AMP synthesis are A) insulin and calcitonin B) glucagon and epinephrine C) aldosterone and testosterone D) parathyroid hormone and glucagon
B. (glucagon and epinephrine)
Which compound is the acceptor of CO2 during photosynthesis? A) ribose-1,6-biphosphate B) ribulose-1,5-bisphosphate C) 3-phosphoglycerate D) glyceraldehyde-3-phosphate E) oxalacetate
B. (ribulose-1,5-bisphosphate)
Which of the following metal ions is not likely to directly participate in a redox reaction at the catalytic center of a redox enzyme? A. Fe2+ B. Cu2+ C. Ca2+ D. Mn2+ E. Fe3+
C. (Ca2+)
Triglyceride absorbed into the lymphatic system is transported to the liver as which of the following? A) Very low density lipoprotein B) Low density lipoprotein C) Chylomicrons D) Liposomes E) Micelles
C. (Chylomicrons)
Glycogen is converted to monosaccharide units by: A. Glucokinase. B. Glucose-6-phosphatase C. Glycogen phosphorylase. D. Glycogen synthase. E. Glycogenase.
C. (Glycogen phosphorylase)
Which of the following compounds is an important intermediate that is found in gluconeogenesis is but not formed in glycolysis? A. Phosphoenolpyruvate B. Glyceraldehyde-3-phosphate C. Oxaloacetate D. NADH
C. (Oxaloacetate)
The steps of glycolysis between glyceraldehyde 3-phosphate and 3 phosphoglycerate involve all of the following except: A. ATP synthesis. B. Catalysis by phosphoglycerate kinase. C. Oxidation of NADH to NAD+. D. The formation of 1,3 bisphosphoglycerate. E. Utilization of Pi.
C. (Oxidation of NADH to NAD+)
Which molecule is a substrate for glycogen synthesis? A) glucose-6-phosphate B) ADP-glucose C) UDP-glucose D) glucose 1,6-bisphosphate
C. (UDP-glucose)
Which of the below is not required for the oxidative decarboxylation of pyruvate to form acetyl-CoA? A) FAD B) Lipoic acid C) CoA-SH D) ATP E) NAD+
D. (ATP)
Which of the following is at a higher level of oxidation than CH3CHO? A) CH3CH2OH B) CH3CH3 C) CH2=CH2 D) CH3CO2H E) none of the above
D. (CH3CO2H)
When the free energy of the products is higher than the free energy of the reactants; such a reaction is referred to as an _____ reaction. A) entropy B) exergonic C) activation D) endergonic
D. (endergonic)
The major atmospheric by-product of photosynthesis is A) nitrogen B) water C) carbon dioxide D) oxygen
D. (oxygen)
In the absence of oxygen, the primary purpose of fermentation is to: A. Produce amino acids for protein synthesis B. Generate a proton gradient for ATP synthesis C. Oxidize glucose to generate reduce electron carriers D. Generate alcohol for beverages E. Regenerate NAD+ from NADH allowing glycolysis to continue
E. (Regenerate NAD+ from NADH allowing glycolysis to continue)
A metabolic pathway that is active catabolically as well as anabolically is called? A) bipolar B) amphother C) bipartite D) departed E) amphibolic
E. (amphibolic)
If the mitochondria cannot pump hydrogen across the intermembrane space, the immediate consequence is that a. ATP synthesis will not occur. b. lactate will accumulate. c. pyruvate will not form. d. sugar will not be hydrolyzed.
a. (ATP synthesis will not occur)
Which of the following is MOST often associated with free fatty acid transport in human blood? a) Albumin b) Globulin c) Cholesterol d) Sphingolipid e) Mucopolysaccharide
a. (Albumin)
Acyl carrier protein and CoA have all of the following in common EXCEPT A) Both incorporate ADP into their structure B) Both incorporate pantothenic acid into their structure C) Both have a functional SH group (thiol group) D) Both form thioester bonds with fatty acids E) Both form high-energy bonds with fatty acids
a. (Both incorporate ADP into their structure)
When the pentose pathway metabolizes glucose, the C-1 of glucose ends up mostly in: a. CO2 b. glycogen c. 3-phosophoglycerate d. pyruvate e. ribulose-5-phosphate
a. (CO2)
When undergoing strenuous anaerobic exercise the Cori Cycle is functioning. Which of the following compounds is being delivered to muscle tissue from the liver as part of this cycle? a. Glucose b. Lactate c. Galactose d. Pyruvate e. Alanine
a. (Glucose)
The figure below is the structure of a partially degraded glycogen. Which of the following statements about the figure is incorrect? A. Glycogen phosphorylase catalyzes the hydrolytic cleavage of residue vii. B. The product of the cleavage reaction catalyzed by Glycogen phosphorylase is glucose 1 phosphate C. In glycogen synthesis, the incoming glucose residue can be added at i or vii D. Glycogen debranching enzyme catalyses the cleavage of alpha1,6 and alpha1,4 glycosidic bonds E. All of the above are correct
a. (Glycogen phosphorylase catalyzes the hydrolytic cleavage of residue vii)
The pentose phosphate pathway is an anabolic reaction that generates NADPH and pentose. This biochemical pathway provides the cell with __________________ for nucleotide and nucleic acid synthesis. a. Ribose-5-phosphate b. Erythose-4-phosphate c. NADPH d. Hydrogen peroxide
a. (Ribose-5-phosphate)
Glucose is stored as the polymer glycogen: A. So that a large amount of glucose can be stored inside cells without causing osmotic problems. B. Because glycogen synthesis does not cost energy. C. Because glycogen is stored extracellularly. D. All of the above. E. None of the above.
a. (So that a large amount of glucose can be stored inside cells without causing osmotic problems)
UDP-glucose pyrophosphorylase catalyzed reaction: G1P → UDP-Glucose (ΔG0' ~ 0). The reaction is made energetically feasible by a. The action of a pyrophosphatase that hydrolyzes pyrophosphate to release energy b. The hydrolysis of UTP c. ATP hydrolysis d. The action of glycogenin
a. (The action of a pyrophosphatase that hydrolyzes pyrophosphate to release energy)
UDP-glucose pyrophosphorylase catalyzed reaction: G1P → UDP-Glucose (ΔG0'~ 0). The reaction is made energetically feasible by A. The action of a pyrophosphatase that hydrolyzes pyrophosphate to release energy B. The hydrolysis of UTP C. ATP hydrolysis D. The action of glycogenin
a. (The action of a pyrophosphatase that hydrolyzes pyrophosphate to release energy)
When a phosphate group is removed from an ATP molecule, a. a substantial amount of energy is released. b. an enzyme is formed c. energy is stored d. activation energy is increased
a. (a substantial amount of energy is released)
The citric acid cycle enzyme ______ contains an iron-sulfur cluster. a) aconitase b) isocitrate dehydrgenase c) succinyl-CoA synthetase d) malate dehydrogenase e) citrate synthase
a. (aconitase)
With respect to the beta-oxidation of palmitate which is true? A) beta-oxidation results in production of 8 acetyl-CoA, 7 NADH and 7 FADH2 B) beta-oxidation results in production of 9 acetyl-CoA, 9 NADH and 9 FADH2 C) beta-oxidation results in production of 8 acetyl-CoA, 8 NADH and 8 FADH2 D) beta -oxidation results in production of 9 acetyl-CoA, 8 NADH and 8 FADH2
a. (beta-oxidation results in production of 8 acetyl-CoA, 7 NADH and 7 FADH2)
The only reaction in the citric-acid cycle in which a carbon-carbon bond is formed is catalyzed by A) citrate synthase B) isocitrate dehydrogenase C) succinyl-CoA synthetase D) fumarase
a. (citrate synthase)
In the reoxidation of QH2 by purified ubiquinone-cytochrome c reductase (Complex III) from heart muscle, the overall stoichiometry of the reaction requires 2 mol of cytochrome c per mole of QH2 because: a) cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor. b) cytochrome c is a two-electron acceptor, whereas QH2 is a one-electron donor. c) cytochrome c is water soluble and operates between the inner and outer mitochondrial membranes d) heart muscle has a high rate of oxidative metabolism, and therefore requires twice as much cytochrome c as QH2 for electron transfer to proceed normally. e) two molecules of cytochrome c must first combine physically before they are catalytically active.
a. (cytochrome c is a one-electron acceptor, whereas QH2 is a two-electron donor)
Catabolism is best described as a. degradative pathways b. biosynthetic pathways c. mechanical pathways d. energy requiring pathways e. none of the above
a. (degradative pathways)
What thermodynamic parameter is a measure of randomness or disorder in a system? a. entropy b. enthalpy c. free energy d. potential energy e. activation energy
a. (entropy)
During glycolysis in the liver, glucose is converted to glucose-6-phosphate by the enzyme(s): a. glucokinase. b. fructokinase. c. hexokinase. d. all of the above. e. none of the above.
a. (glucokinase)
Cyclic 3', 5'-AMP increases the rate of glycogen breakdown (glycogenolysis) by a) promoting the formation of a phosphorylated form of glycogen phosphorylase. b) serving as a substrate for glycogen phosphorylase. c) serving as a precursor of 5' AMP which is a cofactor for glycogen phosphorylase. d) furnishing phosphate for the phosphorolysis of glycogen.
a. (promoting the formation of a phosphorylated form of glycogen phosphorylase)
Because of photosynthesis a) the atmosphere is rich in oxygen gas b) plants produce carbon dioxide c) animals can get energy directly from the sun d) all of the above
a. (the atmosphere is rich in oxygen gas)
Transketolases transfer carbon units: a) 1. b) 2. c) 3. d) 4. e) 5.
b. (2)
The chemical energy generated by mitochondrial electron transport results from which of the following? a) Excess H+ in the matrix b) A H+ gradient across the inner membrane c) The formation of thioesters in the matrix d) A conformational change in the inner membrane
b. (A H+ gradient across the inner membrane)
Products of the light reactions of photosynthesis that are required by the dark reaction are A) oxygen and ATP B) ATP and NADPH C) water and oxygen D) oxygen and NADPH
b. (ATP and NADPH)
Inner mitochondrial membrane does not allow the free movement of one of the following compounds. a. O2 b. ATP c. CO2 d. H2O
b. (ATP)
Cyclic electron flow in chloroplasts produces: a) ATP and O2, but not NADPH. b) ATP, but not NADPH or O2 . c) NADPH, and ATP, but not O2 . d) NADPH, but not ATP or O2 . e) O2, but not ATP or NADPH.
b. (ATP, but not NADPH or O2)
During electron transport, protons are NOT pumped out of the mitochondrion at this site: A) Complex I B) Complex II C) Complex III D) Complex IV
b. (Complex II)
An enzyme involved in the glycogen breakdown to glucose will be allosterically _______ in presence of excess ATP? a. Upregulated b. Downregulated c. Will have no effect d. ATP is not an allosteric regulator
b. (Downregulated)
Malonate is a competitive inhibitor of succinate dehydrogenase. If malonate is added to a mitochondrial preparation that is oxidizing pyruvate as a substrate, which of the following compounds would you expect to decrease in concentration? a) Citrate b) Fumarate c) Isocitrate d) Pyruvate e) Succinate
b. (Fumarate)
In which of the following metabolic conversions is ATP "consumed" during glycolysis? a. 1,3-Bisphosphoglycerate → 3-phosphoglycerate b. Glucose → glucose-6-phosphate c. 2-Phosphoglycerate → 3-phosphoglycerate d. Fructose-1,6-bisphosphate → dihydroxyacetone phosphate + glyceraldehyde-3- phosphate e. Glucose-6-phosphate → fructose-6-phosphate
b. (Glucose → glucose-6-phosphate)
Regarding the synthesis of ketone bodies, which of the following is TRUE? A) Ketone bodies are synthesized for stored energy during the fed state B) HMG CoA is an intermediate that is converted into acetoacetate C) Acetoacetate is converted to beta-hydroxybutyrate spontaneously, yielding a CO2 D) Ketone bodies are produced in the brain in response to starvation E) In the liver, most acetoacetate produced can be converted to acetoacetyl-CoA
b. (HMG CoA is an intermediate that is converted into acetoacetate)
Concerning the fatty acid synthase complex, all of the following are true EXCEPT A) Products include NADP+ and CoA B) Products include stearate (C18:0) and CO2 C) Substrates include acetyl CoA D) Substrates include malonyl CoA E) Substrates include NADPH
b. (Products include stearate, C18:0, and CO2)
Below are the standard reduction potentials (E'°) for two conjugate redox pairs: Pyruvate-/lactate- E'° = -0.185v NAD+/NADH E'° = -0.320v Which of the following is true? A. The pyruvate/lactate conjugate redox pair has a greater tendency to lose electrons than the NAD+/NADH redox pair. B. Pyruvate has a greater affinity for electrons than NAD+. C. NAD+ is a reducing agent. D. Under standard conditions, NAD+ is more likely to be converted to NADH, than pyruvate is to be converted to lactate. E. none of the above.
b. (Pyruvate has a greater affinity for electrons than NAD+)
Below are the standard reduction potentials (E'°) for two conjugate redox pairs: Pyruvate-/lactate- E'° = -0.185v NAD+/NADH E'° = -0.320v Which of the following is true? a) The pyruvate/lactate conjugate redox pair has a greater tendency to lose electrons than the NAD+/NADH redox pair. b) Pyruvate has a greater affinity for electrons than NAD+. c) NAD+ is a reducing agent. d) Under standard conditions, NAD+ is more likely to be converted to NADH, than pyruvate is to be converted to lactate. e) none of the above.
b. (Pyruvate has a greater affinity for electrons than NAD+)
The chemical energy generated by mitochondrial electron transport results from which of the following? A. Excess H+ in the matrix B. a H+ gradient across the inner membrane C. The formation of thioesters in the matrix D. A conformational change in the inner membrane
b. (a H+ gradient across the inner membrane)
Which is a reactant in the Krebs Cycle? a. CO2 b. acetyl-CoA c. NADPH d. FADH2
b. (acetyl-CoA)
Anabolism is best described as A) degradative pathways B) biosynthetic pathways C) mechanical pathways D) energy producing pathways E) none of the above
b. (biosynthetic pathways)
Anabolism is best described as a. degradative pathways b. biosynthetic pathways c. mechanical pathways d. energy producing pathways e. none of the above
b. (biosynthetic pathways)
Glycolysis takes place in a. mitochondria b. cytosol c. endoplasmic reticulum d. golgi apparatus e. none of the above
b. (cytosol)
When the free energy of the products is greater than the free energy of the reactants, such a reaction is referred to as an _____ reaction. a. entropy b. endergonic c. exergonic d. activation
b. (endergonic)
When the free energy of the products is higher than the free energy of the reactants; such a reaction is referred to as an ______________ reaction. a. entropy b. endergonic c. exergonic d. activation e. thermo neutral
b. (endergonic)
Two hormones which act similarly to increase glycogen and lipid breakdown as well as cyclic AMP synthesis are A) insulin and calcitonin B) glucagon and epinephrine C) aldosterone and testosterone D) parathyroid hormone and glucagon
b. (glucagon and epinephrine)
When a muscle is stimulated to contract aerobically, less lactic acid is formed than when it contracts anaerobically because: a. glycolysis does not occur to any significant extent under aerobic conditions. b. under aerobic conditions most of the pyruvate generated as a result of glycolysis is oxidized by the citric acid cycle rather than reduced to lactate. c. The lactic acid generated is rapidly incorporated into lipids under aerobic conditions d. Under aerobic conditions in muscle, the major energy-yielding pathway is the pentose phosphate pathway, which does not produce lactate. e. Muscle is metabolically less active under aerobic than anaerobic conditions.
b. (under aerobic conditions most of the pyruvate generated as a result of glycolysis is oxidized by the citric acid cycle rather than reduced to lactate)
Given that the standard reduction potential of oxaloacetate is -0.166 V and the standard reduction potential of NAD+ is -0.315 V. What is the DE°' for the oxidation of malate by NAD+: Malate + NAD+ → Oxaloacetate + NADH + H+ a) -4.81 V b) + 4.81 V c) -0.149 V d) +0.149 V e) +0.0523 V
c. (-0.149 V)
When O2 instead of CO2 enters in Calvin cycle, ______ is directly produced in addition to 3-phosphoglycerate. a) CO2 b) Sedoheptulose-1,7-bisphosphate (S-1,7-P) c) 2-Phosphoglycolate (2PG) d) Ribulose-5-phosphate (R5P) e) None of them
c. (2-Phosphoglycolate)
One of the following is not a fate of pyruvate? a. Conversion to lactate b. Conversion to CO2 and H2O c. Conversion to NAD+ d. Conversion to ethanol
c. (Conversion to NAD+)
The metabolic basis of fructose intolerance is: a. Deficiency of Glucokinase b. Deficiency of Fructokinase c. Deficiency of Fructose-1-phosphate aldolase d. Deficiency of Hexokinase e. Deficiency of Enolase
c. (Deficiency of Fructose-1-phosphate aldolase)
How many ATP molecules are made per glucose in the second half of the glycolysis pathway? A) None B) Two C) Four D) Three E) Six
c. (Four)
Which sequence accurately reflects the flow of electrons in photosynthesis? A) H2O → PS I → PS II → NADP B) PS II → PS I → NADP →H2O C) H2O → PS II → PS I → NADP D) PS I → PS II → NADP → H2O
c. (H2O → PS II → PS I → NADP)
Which of the following enzymes is not involved in decarboxylation? a. Pyruvate dehydrogenase complex b. Isocitrate dehydrogenase c. Malate dehydrogenase d. α-ketoglutarate dehydrogenase
c. (Malate dehydrogenase)
Heterotrophs are organisms that a. Produce food form inorganic molecules or sunlight. b. Can survive without energy. c. Must consume other organisms to get energy. d. None of the above
c. (Must consume other organisms to get energy)
There is an oxidative and a non-oxidative phase in the pentose phosphate pathway. Which of the following is produced during the oxidative phase? a. Glucose-6-phosphate b. NADP+ c. NADPH d. Both A and C
c. (NADPH)
Which of the following compounds is an important intermediate that is found in gluconeogenesis is but not formed in glycolysis? a. Phosphoenolpyruvate b. Glyceraldehyde-3-phosphate c. Oxaloacetate d. NADH
c. (Oxaloacetate)
The steps of glycolysis between glyceraldehyde 3-phosphate and 3 phosphoglycerate involve all of the following except: a. ATP synthesis. b. Catalysis by phosphoglycerate kinase. c. Oxidation of NADH to NAD+. d. The formation of 1,3 bisphosphoglycerate. e. Utilization of Pi.
c. (Oxidation of NADH to NAD+)
As a result of glycolysis only a small portion of the energy of glucose has been converted to ATP. At this point, the majority of the usable energy is contained in: A) oxidized electron carrier NAD+ B) carbon dioxide C) reduced electron carrier NADH and pyruvate D) acetyl coenzyme A E) pyruvate only
c. (reduced electron carrier NADH and pyruvate)
In eukaryotes, the enzymes that catalyze the reactions of citric acid cycle are located in. a) the cell nucleus. b) the endoplasmic reticulum. c) the mitochondria. d) the lysosomes. e) the cytosol.
c. (the mitochondria)
The tricarboxylic acid cycle is initiated by the condensation of which of the following two molecules? A) Pyruvate and malate B) NAD+ and oxaloacetate C) NAD+ and oxalosuccinate D) Acetyl coenzyme A and oxaloacetate E) Acetyl coenzyme A and oxalosuccinate
d. (Acetyl coenzyme A and oxaloacetate)
The tricarboxylic acid cycle is initiated by the condensation of which of the following two molecules? A) Pyruvate and malate B) NAD+ and oxaloacetate C) NAD+ and oxalosuccinate D) Acetyl coenzyme A and oxaloacetate E) Acetyl coenzyme A and oxalosuccinate
d. (Acetyl coenzyme A and oxaloacetate)
A novel chemotherapeutic agent for treating cancer is found to have increased phosphoenolpyruvate (PEP) levels and decreased pyruvate levels as a side effect. Which enzyme might this chemotherapeutic agent be inadvertently targeting? A. hexokinase B. pyruvate dehydrogenase C. glucose-6-phosphatase D. Phosphoenolpyruvate Carboxykinase E. isocitrate dehydrogenase
d. (Phosphoenolpyruvate Carboxykinase)
A novel chemotherapeutic agent for treating cancer is found to have increased phosphoenolpyruvate (PEP) levels and decreased pyruvate levels as a side effect. Which enzyme might this chemotherapeutic agent be inadvertently targeting? a. hexokinase b. pyruvate dehydrogenase c. glucose-6-phosphatase d. Phosphoenolpyruvate Carboxykinase e. isocitrate dehydrogenase
d. (Phosphoenolpyruvate Carboxykinase)
At the end of glycolysis, each molecule of glucose has yielded 2 molecules of _______, 2 molecules of ________, and a net of 2 molecules of _________. A. FAD; NAD+; ADP B. CO2; NAD+; ADP C. Lactic acid; ethanol; CO2 D. Pyruvate, NADH, ATP E. H2O; CO2; ATP
d. (Pyruvate, NADH, ATP)
If you injected glucagon into the blood of someone, you would expect to see: A. a decrease in liver fructose-2,6-bisphosphate concentration. B. a decrease in the rate of glycolysis in liver. C. increased release of glucose to the blood from the liver. D. all of the above. E. None of the above
d. (all of the above)
If you injected glucagon into the blood of someone, you would expect to see: a. a decrease in liver fructose-2,6-bisphosphate concentration. b. a decrease in the rate of glycolysis in liver. c. increased release of glucose to the blood from the liver. d. all of the above. e. None of the above.
d. (all of the above)
Glycolysis takes place in a. mitochondria b. golgi apparatus c. endoplasmic reticulum d. cytosol e. none of the above
d. (cytosol)
Complete the following statement correctly: FAD is a prosthetic group, ..... a) ...it is readily exchanged with the solvent. b) ...it is loosely associated with the protein. c) ...it is an artificial substitute for NADH. d) ... it is tightly bound to the enzyme. e) ...it needs to be cleaved to activate the enzyme.
d. (it is tightly bound to the enzyme)
In plants and cyanobacteria, Photosystem II _____, and Photosystem I _____. a) oxidizes O2...reduces FAD b) oxidizes H2O...reduces FAD+ c) oxidizes H2O...reduces NAD d) oxidizes H2O...reduces NADP+ e) none of the above
d. (oxidizes H2O...reduces NADP+)
The conversion of 1 mole of pyruvate to 3 moles of CO2 via the pyruvate dehydrogenase and the TCA cycle also yields ____ moles of NADH, ____ moles of FADH2, and ____ moles of ATP (or GTP). A. 3; 2; 0 B. 3; 1; 1 C. 2; 2; 2 D. 4; 2; 1 E. 4; 1; 1
e. (4; 1; 1)
Which of the following is NOT true? A. Glucagon causes the breakdown of glycogen in liver to yield glucose to the blood. B. Insulin inhibits glycogenolysis in the liver. C. Epinephrine causes the glycogen in liver to be degraded to yield glucose to the blood. D. Insulin increases the transport of glucose into muscle cells. E. Epinephrine inhibits glycolysis of glucose in muscle cells.
e. (Epinephrine inhibits glycolysis of glucose in muscle cells)
This enzyme is responsible for eliminating limit branch during glycogenolysis a) UDP-glucose pyrophosphorylase. b) Glycogen synthase c) Glycogen phosphorylase d) Phosphoglucomutase e) Glycogen debranching enzyme
e. (Glycogen debranching enzyme)
This enzyme is responsible for generating the minor product of glycogenolysis a) UDP-glucose pyrophosphorylase. b) Glycogen synthase c) Glycogen phosphorylase d) Phosphoglucomutase e) Glycogen debranching enzyme
e. (Glycogen debranching enzyme)
In most tissues, an increase in the following ratio directly causes an increase in glycolysis activity: a. FADH2/FAD b. ATP/ADP c. GTP/GDP d. NADH/NAD+ e. NAD+/NADH
e. (NAD+/NADH)
In most tissues, an increase in the following ratio directly causes an increase in glycolysis activity: a. FADH2/FAD b. ATP/ADP c. GTP/GDP d. NADH/NAD+ e. NAD+/NADH
e. (NAD+/NADH)
Which combination of cofactors is involved in the conversion of pyruvate to acetyl- CoA? a) Biotin, FAD, and TPP b) Biotin, NAD+, and FAD c) NAD+, biotin, and TPP d) Pyridoxal phosphate, FAD, and lipoic acid e) TPP, lipoic acid, and NAD+
e. (TPP, lipoic acid, and NAD+)
Which of the following is not a part of the electron transport chain? A) cytochrome B) FADH2 C) coenzyme Q D) NADH E) coenzyme A
e. (coenzyme A)
Enzymes accelerate thermodynamically possible reactions by: a. systematically removing one of the products b. lowering the overall free energy change for the reaction c. reducing the temperature coefficient d altering the equilibrium constant e. lowering the activation energy of the reaction
e. (lowering the activation energy of the reaction)
