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| 1 |
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Q:
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Where does the Krebs Cycle occur in human beings? |
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A
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Mitochondrial matrix |
B
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Outer mitochondrial membrane |
C
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Inner mitochondrial membrane |
D
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Intermembrane space of the mitochondria |
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Tags:
Citric Acid Cycle | Eukaryotic Cells | |
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| 2 |
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Q:
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In the absence of oxygen, pyruvate from glycolysis cannot be further utilized for energy synthesis through the Krebs cycle because |
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A
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Oxygen is needed to react with pyruvate and convert it to acetyl CoA |
B
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Glycolysis becomes more energetically favorable than the Krebs cycle, thus pyruvate circulates through glycolysis for energy synthesis |
C
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There is not NAD+ to react with pyruvate and convert it to acetyl CoA |
D
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Oxygen drives the entrance of pyruvate into the Krebs cycle |
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Tags:
Citric Acid Cycle | |
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| 3 |
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Q:
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Shown below is the first step of the reaction catalyzed by citrate synthase. Outlined in the grey box is a molecule involved in the Tricarboxylic Acid Cycle. What is the name of the functional group of the molecule that is directly involved in the reaction?
 |
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A
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Acetyl |
B
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Carboxyl |
C
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Methoxyl |
D
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Methanoate |
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Tags:
Citric Acid Cycle | |
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| 4 |
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Q:
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One of the steps of the citric acid cycle is the conversion of succinate to fumarate, which results in the reduction of FAD. This process is shown by the diagram below. Which of the following statements is(are) true regarding the reaction that occurs?
I. Fumarate will rotate polarized light differently than succinate does.
II. FAD becomes reduced to FADH2
III. The chemical potential energy of fumarate is lower than succinate.
 |
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A
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III only |
B
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I and III only |
C
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II and III only |
D
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I, II, and III |
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Tags:
Citric Acid Cycle | Atomic & Electronic Structure | Redox Reactions | Molecular Bonding | |
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| 5 |
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Q:
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In the Krebs cycle, malate and NAD+ are converted to NADH and oxaloacetate. The malate converts to oxaloacetate by having one of its alcohol groups converted into a carbonyl. From the perspective of malate, this type of reaction is an example of which of the following? |
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A
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reduction |
B
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oxidation |
C
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dehydration |
D
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condensation |
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Tags:
Citric Acid Cycle | Redox Reactions | |
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| 6 |
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Q:
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Carnitine is a compound required for the transport of fatty acids from the cytosol into the mitochondria. A carnitine deficiency would most directly impact which of the following metabolic reactions? |
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A
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Gluconeogenesis |
B
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Krebs Cycle |
C
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Electron Transport Chain |
D
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Glycolysis |
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Tags:
Citric Acid Cycle | |
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| 9 |
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Q:
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Which of the following is NOT correct in regard to fatty acid transport into the mitochondrial matrix?
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A
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Fatty acid transport into the mitochondrial matrix is the rate-limiting step in beta oxidation.
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B
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The inner mitochondrial membrane is impermeable to fatty acyl CoA.
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C
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A specialized carrier system transports activated fatty acids from the cytosol to mitochondria.
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D
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Fatty acyl groups that enter the matrix are not committed to oxidation to acetyl-CoA.
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Tags:
Citric Acid Cycle | Metabolism of Fatty Acids and Proteins | Membrane Transport and Signalling | |
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| 10 |
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Q:
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Fatty acid metabolism leads directly to the Krebs cycle, suggesting that the fatty acids must first be transported: |
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A
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into the matrix of the mitochondria. |
B
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into the intermembrane space of the mitochondria. |
C
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into the lumen of the ER. |
D
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into the nucleus. |
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Tags:
Citric Acid Cycle | |
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| 11 |
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Q:
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The relase of CO2 during the Krebs cycle is a result of which type of reaction? |
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A
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decarboxylation |
B
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carbonyl reduction |
C
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carbonic acid neutralization |
D
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beta-oxidation |
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Tags:
Carboxylic Acids | Citric Acid Cycle | |
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| 13 |
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Q:
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After Glycolysis and the Citric Acid Cycle (Kreb's Cycle), most of the energy from the original glucose molecule is now in the form of what? |
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A
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Pyruvate |
B
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ATP |
C
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H2O
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D
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High-energy electrons associated with electron carriers
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Tags:
Glycolysis, Gluconeogenesis, PPP | Citric Acid Cycle | |
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| 14 |
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Q:
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The deamination of alanine produces a carbon compound which then enters the Citric Acid Cycle. What is the identity of this carbon compound? |
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A
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Succinate |
B
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Acetyl-CoA
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C
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Malate |
D
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Fumarate |
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Tags:
Citric Acid Cycle | Oxidative Phosphorylation | |
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| 15 |
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Q:
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Mature red blood cells have hemoglobin and no organelles. These cells metabolize glucose, which generates lactate, and can be used by the liver in gluconeogenesis. Which of the following does NOT explain why mature red blood cells metabolize glucose to lactate in order to generate energy? |
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A
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Anaerobic oxidation of pyruvate regenerates the NAD+ required for glycolysis to continue |
B
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Oxygen is not available for the aerobic oxidation of glucose |
C
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Mature red blood cells have no citric acid cycle |
D
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Mature red blood cells have no mitochondria |
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Tags:
Glycolysis, Gluconeogenesis, PPP | Circulatory System | Citric Acid Cycle | |
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| 16 |
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Q:
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Which of the following is correct about the beta oxidation of fatty acids?
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A
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Occurs in the intermembrane space of the mitochondria
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B
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Produces one molecule each of NADPH and FADH2 in a single round
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C
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Is the same for unsaturated and saturated fatty acids
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D
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Produces two-carbon molecules that then enter the Citric Acid Cycle
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Tags:
Oxidative Phosphorylation | Metabolism of Fatty Acids and Proteins | Citric Acid Cycle | |
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| 17 |
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Q:
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In humans, proline can be synthesized from glutamate which in turn can be derived from α-ketoglutarate. It can therefore be concluded that: |
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A
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proline is necessary for the Krebs cycle. |
B
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glutamate and proline play similar roles in proteins. |
C
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proline production is an irreversible reaction in the body. |
D
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proline is not an essential amino acid in humans. |
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Tags:
Citric Acid Cycle | Miscellaneous Biochemistry | |
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| 18 |
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Q:
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The conversion of oxaloacetate to citrate in the Krebs cycle requires the addition of how many carbon atoms? |
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Tags:
Citric Acid Cycle | |
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| 19 |
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Q:
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In the citric acid cycle, how many molecules of ATP are produced per molecule of acetyl CoA that enters the cycle? |
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Tags:
Citric Acid Cycle | |
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| 20 |
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Q:
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Which of the following molecules can be converted into acetyl-CoA and used for energy within the citric acid cycle?
I. fats
II. carbohydrates
III. proteins |
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A
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II only |
B
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II and III only |
C
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I and II only |
D
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I, II, and III |
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Tags:
Citric Acid Cycle | |
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| 21 |
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Q:
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Within the citric acid cycle, malate dehydrogenase converts malate to oxaloacetate. The reaction utilizes NAD+ from which an NADH molecule is produced. This reaction serves as an example of: |
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A
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elimination. |
B
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combustion. |
C
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oxidation reduction. |
D
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decarboxylation. |
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Tags:
Citric Acid Cycle | |
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| 22 |
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Q:
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How many molecules of NADH are produced from 2 glucose molecules through the citric acid cycle? |
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Tags:
Citric Acid Cycle | |
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| 23 |
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Q:
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Which of the following is true regarding the electron carrying ability of NADH and FADH2? |
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A
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FADH2 produces double the ATP molecules than that produced by NADH |
B
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FADH2 produces half the ATP molecules than that produced by NADH |
C
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FADH2 produces the same number of ATP molecules produced by NADH |
D
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FADH2 produces less ATP molecules than that produced by NADH but greater than half |
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Tags:
Citric Acid Cycle | |
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