Oxidative Phosphorylation - Sante Medical College PDF

1. Which of the following molecules is central to most of the biological reactions in the cell during metabolism? A. Acetyl CoA B. Ethanol C. Lipoamide D. Glucose E. Acetaldehyde 2. Which of the following statemen...

1. Which of the following molecules is central to most of the biological reactions in the cell during metabolism? A. Acetyl CoA B. Ethanol C. Lipoamide D. Glucose E. Acetaldehyde 2. Which of the following statements is not true regarding the citric acid cycle? A. The oxaloacetate, a TCA cycle intermediate, acts as a precursor for the synthesis of aspartate, asparagine, methionine, and threonine. B. The citric acid cycle enables the yeast or a bacterial cell to get metabolic energy from acetyl Co-A in the absence of oxygen. C. The catabolic breakdown of amino acids produces the intermediates of the TCA cycle. D. In the absence of oxygen, the acetyl Co-A can’t enter the TCA cycle, so the yeast produces energy by converting pyruvate to ethanol. E. During anabolism of amino acids, the intermediates of the TCA cycle are used to synthesize the amino acids like glutamine, glutamate, proline, and arginine. 3. Which of the following statement is not true regarding the pyruvate dehydrogenase enzyme? A. The pyruvate dehydrogenase enzyme is a very large multimeric complex composed of three subunits named E1, E2, and E3 B. The enzyme pyruvate dehydrogenase converts the pyruvate to acetyl Co-A via decarboxylation in the presence of oxygen. C. The pyruvate dehydrogenase enzyme converts the acetaldehyde to ethanol in the yeast cell in the absence of oxygen. D. The pyruvate dehydrogenase enzyme is a mitochondrial enzyme. E. The E2 subunit of pyruvate dehydrogenase enzyme converts the TPP-acetaldehyde to acetyl-lipoamide, whereas the E3 subunit coverts the acetyl-lipoamide to acetyl-CoA 4. Which of the following amino acids is not synthesized from α-ketoglutarate of the citric acid cycle? A. Glutamine B. Proline C. Arginine D. Tyrosine E. Glutamate 5. Which of the following is not correctly matched? A. Citrate — allosteric effector for some enzymes B. Malate — generates FADH2 when it is converted to oxaloacetate C. α-Ketoglutarate — used in amino acid and nitrogen metabolism D. Fumarate — important in nucleotide metabolism E. Succinyl-CoA — used to make heme 6. Which of the following is correct regarding the energy output per cycle of the citric acid cycle? A. 1 NADH2, 1 FADH2, and 3 GTP B. 3 NADH, 1 FADH2, and 1 GTP/ATP C. 1 NADH2, 3 FADH2, and 1 ATP D. 1 NADH2, 1 FADH2, and 1 ATP E. 1 NADH2, 3 FADH2, and 3 ATP 7. Which of the following enzymes of the citric acid cycle is embedded in the inner mitochondrial membrane? A. Aconitase B. Isocitrate dehydrogenase C. Succinate dehydrogenase D. Malate dehydrogenase E. α-ketoglutarate dehydrogenase 8. Which of the following enzymes participates in both the TCA cycle and the ETC? A. Fumarase B. Isocitrate dehydrogenase C. Succinate dehydrogenase D. Malate dehydrogenase E. α-Ketoglutarate dehydrogenase 9. How many oxidation reactions take place in the citric acid cycle? A. Three B. One C. Four D. Five E. Two 10.Which of the following statements is not correct regarding the glyoxylate cycle? A. In the glyoxylate cycle, there is no net production of CO2 molecules B. The glyoxylate pathway is found in plants and bacteria only C. The glyoxylate pathway helps the bacterial cell to carry out the gluconeogenesis by using Acetyl-CoA as a carbon source D.The glyoxylate cycle helps to bypass the decarboxylation steps of the citric acid cycle E. The glyoxylate cycle is exclusive to the muscle cells as it helps in the synthesis of glucose from the acetyl-CoA during contraction process 11. Which of the following enzymes are unique to the glyoxylate cycle? A. Succinate dehydrogenase B. Malate dehydrogenase C. Isocitrate lyase D. Malate synthase E. Citrate synthase 12. Which of the following molecules acts as a branch point between the synthesis of ketone bodies and cholesterol in animal bodies? A. D-β-hydroxybutyrate B. Acetoacetyl-CoA C. Acetoacetate D. β-hydroxy-β-methylglutaryl-CoA E. Mevalonate 13. Which of the following enzymes is not a part of ketone body metabolism? A. FBPase B. Thiolase C. HMG-CoA synthetase D. β-hydroxybutyrate dehydrogenase E. HMG-CoA lyase