MCQ on Glucose Metabolism & Enzyme

MCQ ON BIOCHEMISTRY (Based on previous year MLT competitive exam) 1. Glycolytic pathway regulation involves A. allosteric stimulation by ADP B. allosteric inhibition by ATP C. feedback, or product, inhibition by ATP D. all of the above 2. A kinase is an enzyme that A. removes phosphate groups of substrates B. uses ATP to add a phosphate group to the substrate C. uses NADH to change the oxidation state of the substrate D. removes water from a double bond # 3. The released energy obtained by oxidation of glucose is stored as A. a concentration gradient across a membrane B. ADP C. ATP D. NAD+ 4. For every one molecule of sugar glucose which is oxidized produced. A. 1 B. 2 C. 3 D. 4 molecule of pyruvic acid are 5. In the glycogen synthase reaction, the precursor to glycogen is A. glucose-6-P B. UTP-glucose C. UDP-glucose D. glucose-1-P 6. The enzymes of glycolysis in a eukaryotic cell are located in the A. intermembrane space B. plasma membrane C. cytosol D. mitochondrial matrix 7. Which of the following is not true of glycolysis? A. ADP is phosphorylated to ATP via substrate level phosphorylation B. The pathway does not require oxygen C. The pathway oxidizes two moles of NADH to NAD+ for each mole of glucose that enters D. The pathway requires two moles of ATP to get started catabo-lizing each mole of glucose. Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com) 8. The glycolytic pathway (glucose → 2 pyruvate) is found A. in all living organisms B. primarily in animals excluding particles C. only in eukaryotes D. only in yeast # 9. Which of the following regulates glycolysis steps? A.Phosphofructokinase B.Hexose kinase C.Pyruvate kinase D.All of these 10. Glucose from the breakdown of glycogen is obtained in A. the liver by phosphorolysis B. the muscles by phosphorolysis C. the muscles by hydrolysis D. both (a) and (b) 11. No of net ATP produced from Glycolysis is? A. 9 B. 7 C. 38 D. 10 TCA Cycle #1. How many molecules of ATPs are synthesized per NADH oxidation? A. 2.5 B. 1.5 C. 3.5 D. 4.5 2. Why is the TCA cycle the central pathway of metabolism of the cell? A. It occurs in the center of the cell B. Its intermediates are commonly used by other metabolic reactions C. All other metabolic pathways depend upon it D. None of the above. # 3. In what form does the product of glycolysis enter the TCA cycle? A. AcetylCoA B. Pyruvate C. NADH Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com) D. Glucose 6. During cellular respiration, most of the ATP made, is generated by A. oxidative phosphorylation B. photophosphorylation C. glycolysis D. substrate-level phosphorylation 9. The enzymes of the TCA cycle in a eukaryotic cell are located in the A. nucleus B. mitochondria C. plasma membrane D. lysosomal bodies 10. Citric acid cycle occurs in A. cytoplasm B. mitochondria C. endoplasmic reticulum D. golgi bodies 11. No of ATP produced from each TCA cycle is A. 20 B. 10 C. 9 D. 13 12. Most of the enzymes of the citric acid cycle in a eukaryotic cell are located in the A. inner mitochondrial membrane B. cytosol C. mitochondrial matrix D. intermembrane space 15. The end product of glycolysis is pyruvate, which enters the citric acid cycle after being converted to A. acetic acid B. acetyl-CoA C. acetaldehyde D. none of these. 18. Which of the following enzyme does not take part in the TCA cycle? A. Citrate synthase B. Iso-citrate dehydrogenase Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com) C. Pyruvate dehydrogenase D. Malate dehydrogenase 19. The first intermediate in TCA cycle is A. succinate B. fumerate C. citrate D. Malate 21. Which one of the following is not the intermediate of Kreb's cycle? A. Isocitrate B. Succinate C. Fumarate D. Stearate 22. How many ATPs are produced during citric acid cycle from 1 molecule of glucose? A. 10 B. 13 C. 20 D. 8 25. In eukaryotes, electron transport occurs in A. membranes of mitochondria B. endoplasmic reticulum C. cytoplasm D. all of the above Oxidative Phosphorylation # 1. FAD is reduced to FADH2 during A. electron transport phosphorylation B. lactate fermentation C. Krebs cycle D. Glycolysis. 2. During glycolysis, electrons removed from glucose are passed to Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com) A. FAD B. NAD+ C. acetyl CoA D. pyruvic acid #5. The carbon dioxide is primary a product of A. Krebs cycle B. glycolysis C. electron transport phosphorylation. D. lactate fermentation. 6. Which of the following is not a feature of oxidative phosphorylation? A. Direct transfer of phosphate from a substrate molecule to ADP B. An electrochemical gradient across the inner mitochondrial membrane C. A membrane bound ATP synthase D. A protonmotive force 10. Lactic acid is produced by human muscles during strenuous exercise because of lack of A. oxygen B. NAD+ C. glucose D. ADP and Pi 11. Which of the following is correct sequence of processes in the oxidation of glucose? A. Krebs cycle - glycolysis - electron transport B. Glycolysis - Krebs cycle - eletron transport C. Electron transport - Krebs cycle - glycolysis D. Krebs cycle - electron transport – Glycolysis 12. In electron transport, electrons ultimately pass to A. ADP B. cytochrome b C. oxygen D. none of these 13. The complete oxidation of glucose yields usable energy in the form of A. FADH2 B. coenzyme A C. ATP D. pyruvic acid Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com) 14. The aerobic breakdown of glucose known as respiration involves A. electron transport phosphorylation B. glycolysis C. Krebs Cycle D. all of the above 15. In aerobic respiration, the compound that enters a mitochondrion is A. acetyl CoA B. pyruvate C. phosphoglyceraldehyde D. Oxaloacetate Enzymes 3. Which of the following statements about enzymes or their function is true? A. Enzymes do not alter the overall change in free energy for a reaction B. Enzymes are proteins whose three-dimensional form is key to their function C. Enzymes speed up reactions by lowering activation energy D. All of the above 6. Vitamin B12 (Cobalamin) is only synthesized by A. fishes B. micro-organisms C. plants D. animals 7. Which of the following are reduced coenzymes? A. NADH and FADH2 B. NAD+ and FAD C. ATP and GTP D. Coenzyme A and ubiquinone 9. Vitamins are essential because the organism A. can't synthesize these compounds at all Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com) B. can synthesize these compounds partially C. can't synthesize these compounds in the adequate amounts D. none of the above 12. Vitamin B12 is useful in the prevention and treatment of A. pernicious anemia B. scurvy C. cataract D. beri-beri 22. The vitamin niacin is part of the A. ferredoxin B. pyridoxal phosphate C. pyrophosphate D. NAD+ molecule. 26. The vitamin riboflavin is part of the A. ferredoxin B. FAD C. pyridoxal phosphat D. pyrophosphate molecule. 29. Lipoic acid is a co-factor of the A. pyruvic dehydrogenase B. α-ketoglutaric dehydrogenase C. both (a) and (b) D. di-hydroorotate dehydrogenase 34. Which of the following compounds/(s) belong/(s) to the vitamin B6 group? A. Pyridoxal B. Pyridoxine C. Pyridoxamine D. All of these 35. What metal ion is specifically bound by vitamin B12? A. Cobalt B. Copper C. Zinc D. Iron 6. Vitamin B12 (Cobalamin) is only synthesized by A. fishes Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com) B. micro-organisms C. plants D. animals 7. Which of the following are reduced coenzymes? A.NADH and FADH2 B.NAD+ and FAD C.ATP and GTP D.Coenzyme A and ubiquinone 9. Vitamins are essential because the organism A. can't synthesize these compounds at all B. can synthesize these compounds partially C. can't synthesize these compounds in the adequate amounts D. none of the above © Created by Kaushik Sen Downloaded by Kaushik Sen (sen.kaushik5896@gmail.com)