Glycolysis and Formation of Acetyl-CoA Worksheet Answers 1. When you eat food that contains carbohydrates, you break down the carbohydrates into a monosaccharide called ______glucose________. If you don’t use this monosaccharide, you body can store it in the liver in the form of _____glycogen_________. 2. When your body metabolizes (breaks down) glucose, whether incompletely or completely, the first pathway glucose molecules have to go through is glycolysis 3. Where does this pathway take place? Cytoplasm of the cell 4. How many molecules of pyruvic acid are made from a single molecule of glucose? 2 5.-6. Where can this product go to next? (broken down completely/incompletely) enters mitochondrion to form Acetyl Co-A accepts e- from NADH to form lactic acid 7. What determines which pathway is taken? Whether O2 is present 8. What molecule stores the high-energy electrons (and hydrogen) removed from glucose in glycolysis? NAD+ 8. How many reduced electron/hydrogen carrier molecules are produced in glycolysis? 2 9. How many net ATP molecules are made during glycolysis? 2 10. Via what process are these ATP molecules made? Substrate level phosphorylation 11. In glycolysis, a molecule of glucose is split into 2 molecules of PGAL These molecules are ultimately converted into 2 pyruvic acid molecules 12. What happens to the high-energy electrons (and hydrogen) held by NADH if there is no O 2 present? If no oxygen is present, the pyruvate must take the electrons (and their hydrogen) back. 13. Explain why this happens. This happens because there are only a small number of NAD+ molecules in the cell. They must be reused to keep glycolysis going with additional glucose molecules. This means they need to “unload” the electrons from NADH by giving them to some other molecule. Since the pyruvate cannot continue on to the Krebs cycle when there is no oxygen present, it receives the electrons. This allows the glycolysis portion of cellular respiration to continue even when O 2 is not present. 14. In the Aerobic System (complete breakdown of glucose), oxygen is the final electron acceptor. 15. In order for pyruvic acid to enter the Citric Acid Cycle/Kreb’s Cycle, it needs to be altered to Acetyl CoA 16. In the above process (#15), how many of these molecules are produced? 2 17. In the above process (#15), how many ATP’s are produced directly? 0 18. In the above process (#15) how many reduced electron/hydrogen carrier molecules are made per pyruvic acid? 1 19. In the above process (#14) how many reduced electron/hydrogen carrier molecules are made per glucose? 2 20. What brings the acetyl group into the Kreb’s Cycle? CoA