Quiz #2 on general biology 1 krebs cycle.pptx

Short quiz on Krebs cycle and respiration

1. Quiz #2: Gen Bio

2. Multiple choice

3. 1. The Krebs cycle occurs in which part of the eukaryotic cell? A. Cytoplasm B. Mitochondrial matrix C. Nucleus D. Golgi apparatus 2. What is the first step of the Krebs cycle? A. Formation of succinate B. Conversion of citrate to isocitrate C. Combination of acetyl-CoA and oxaloacetate to form citrate D. Oxidation of fumarate to malate 3. Which molecule is directly produced in the Krebs cycle through substrate-level phosphorylation? A. NADH B. FADH₂ C. GTP (or ATP) D. CO₂

4. 4. The enzyme that catalyzes the first step of the Krebs cycle is: A. Aconitase B. Citrate synthase C. Isocitrate dehydrogenase D. Succinyl-CoA synthase 5. How many molecules of CO₂ are released per turn of the Krebs cycle? A. 1 B. 2 C. 3 D. 4 6. Which step of the Krebs cycle produces FADH₂? A. Step 3 – Isocitrate dehydrogenase B. Step 5 – Succinyl-CoA synthase C. Step 6 – Succinate dehydrogenase D. Step 7 – Malate dehydrogenase

5. 7. What is the main function of the Krebs cycle? A. To split glucose into pyruvate B. To produce energy-rich molecules for ATP formation C. To absorb light energy for photosynthesis D. To synthesize fatty acids 8. Which molecule combines with acetyl-CoA to start the cycle? A. Citrate B. Pyruvate C. Oxaloacetate D. Malate 9. The total energy yield from one turn of the Krebs cycle is: A. 2 ATP, 2 NADH, 1 FADH₂ B. 1 ATP (or GTP), 3 NADH, 1 FADH₂ C. 3 ATP, 3 NADH, 1 CO₂ D. 2 GTP, 2 NADH, 2 FADH₂

6. 10. Which scientist discovered the Krebs cycle? A. Hans Krebs B. Louis Pasteur C. Albert Szent-Györgyi D. Melvin Calvin 11. Which of the following processes requires oxygen? A. Fermentation B. Glycolysis C. Aerobic respiration D. Lactic acid formation 12. What is the final electron acceptor in aerobic respiration? A. CO₂ B. H₂O C. O₂ D. NADH

7. 13. Which process produces more ATP? A. Aerobic respiration B. Anaerobic respiration C. Glycolysis only D. Alcoholic fermentation 14. Anaerobic respiration takes place in the absence of: A. Water B. Oxygen C. Carbon dioxide D. Sunlight 15. What is a byproduct of anaerobic respiration in muscle cells? A. Ethanol B. Lactic acid C. Carbon dioxide D. Water

8. 16. How many ATP are produced in krebs cycle from one glucose molecule? A. 2 (GTP) B. 4 C. 18 D. 36-38 17. In yeast cells, anaerobic respiration results in the production of: A. Ethanol and carbon dioxide B. Lactic acid C. Acetyl-CoA D. Oxygen and glucose 18. Which of the following best describes anaerobic respiration? A. Uses oxygen to generate ATP B. Produces less energy than aerobic respiration C. Takes place in the mitochondria D. Generates water as a product

9. 19. During glycolysis, NAD+ is reduced to: A. FADH₂ B. NADH C. ATP D. Pyruvate 20. How many net ATP molecules are produced from one glucose molecule in glycolysis? A. 2 B. 4 C. 6 D. 8