Question

� Remember: H �H⁺� e^- Youcannot use these terms interchangeably

� Web links for additional help provided atthe end of this workshop

1. (0.5) In the catabolic pathways of glycolysis and the citricacid cycle, organic food molecules, are oxidized /reduced (circle one) to CO₂. The H from thesemolecules ends up primarily on the coenzyme NADH. NADH is oxidized / reduced (circle one) comparedto NAD⁺.

The energy from NADH powers the electron transport chain.Explain in detail what happens to the H+ and the e- from the H thefollowing questions.

1. (0.5) Is the flow of electrons exergonic (-G) or endergonic(+G)?

1. (1) Where do the electrons flow from, through, and to? Be verydetailed in this answer.

1. (0.5) Is the making of a proton gradientendergonic or exergonic (circleor underline one)?

1. (0.5) Is this active transport orpassive transport of protons (circle or underlineone)?

1. (1.5) How is the flow of electrons related to the establishmentof the proton gradient? This is an important one�Explain fully.

1. (1) What is the role of oxygen in making ATP?
2. (1) What is proton motive force?

1. (0.5) Is ADP + P_i � ATP exergonicor endergonic (circle or underline one)?

1. (0.5) What is the product of substrate-levelphosphorylation?

1. (1) When you burn fat for food, what happens to the carbons inthe triglycerides? (what is the last molecule of which they are apart?)

1. (1.5) Cyanide binds to the iron in cytochrome c oxidase andprevents this enzyme from transferring electrons to oxygen.Describe how this would change

1. How oxygen is used
2. The proton gradient
3. ATP levels

1. (1) Victims of cyanine poisoning often show an increased levelof lactic acid in the brain. Explain why this happens, includingall the products of all the relevant pathways.

1. (1) Imagine that you are examining the effect of prolonged,low-dose exposure of mice to cyanide and you found that liverweight decreased slightly but significantly in the experimentalmice. What would be your explanation of this phenomenon?