1. Pyruvate is metabolized to _CARBON DIOXIDE_ in aerobic metabolism, to __ETHANOL_ in fermentation, and to _LACTIC ACID_ in anaerobic muscle metabolism. What intermediate in metabolism controls the choice of metabolic direction from pyruvate? NADH
2. What is the difference in yield of ATP between complete aerobic and anaerobic metabolism of glucose?
Pathway Conditions | ATP Yield |
| aerobic glucose metabolism | 38 |
| anaerobic glucose metabolism | 2 |
3. (a) What role do the (1) electron transport chain, the (2) proton gradient, and (3) ATP synthase have in the chemiosmotic theory of ATP synthesis?
(1) The role of the ETC is to move the electrons from the higher energy state in NADH to a terminal acceptor of the electrons (oxygen) in discrete steps some of which are used to pump protons across the mitochondrial membrane.
(2) The role of the proton gradient to to provide the potential energy necessary to drive ATP synthesis.
(3) The role of the ATP synthase is to synthesis ATP from ADP utilizing the potential energy in the proton gradient that is released through the Synthase.
(b) Where in what organelle does this process take place?
Process takes place in the inner mitochondrial membrane of the mitochondria.
4. Postulate how light can be used as an energy source in the electron transport chain. What common goal do the electron chains from plants and animals have? What common product do they have?
Light energy provides high energy electrons that initiate the electron transport chain in plants. The common goal for each of these processes is to store energy for synthesis in the form of ATP. Plants use the electron transport chain to perform chemisomotic synthesis of ATP and also provide sufficient energy from the excited electron to synthesize NADPH from NADP+. Animal cells use the elctron trasnport chain to synthesize ATP using the chemiosmotic process. The common product of the two systems is ATP.
5. Bonus Class Question: Give the General Path for connecting glucose oxidation with oxygen reduction. (Fill in the diagram given on the board.)