1. How do enzymes regulate the rate of chemical change? How does the specificity of an enzyme depend on its structure? How is the activity of an enzyme regulated? What is the role of ATP in coupling the cells anabolic and catabolic processes?

2. Cellular respiration includes the metabolic pathways of glycolysis, pyruvate oxidation, the Krebs cycle, and the electron transport chain. ln cellular respiration, carbohydrates and other metabolites (i.e. glycerol and fatty acids) are oxidized, and the resulting energy-transfer reactions support the synthesis of ATP. Using the information above, describe one contribution of each of the following in ATP synthesis.

a. Catabolism of glucose in glycolysis and pyruvate oxidation

b. Oxidation of intermediates in the Krebs cycle formation of a proton gradient by the electron transport chain.