Week 7 Review Sheet answers

Week 7 Review Sheet answers - Final Review Sheet Week 7...

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Final Review Sheet – Week 7 Lecture 17 Electron transport and oxidative phosphorylation Main Points Be clear on oxidation/reduction/oxidizing agent/reducing agent. Strength of a reducing agent is measured on the redox potential scale by comparison to H + - H 2 . Molecules that are strong reducing agents tend to give up their electrons easily and are more negative n the redox potential scale. Electrons flow spontaneously from negative to positive redox potentials, so such flow has a negative G and releases energy. Once can calculate the amount of energy released by the equation: Note here when you use this equation: In class, the example I gave was for NADH which has a negative redox potential. So, when you find the difference between the redox potential of O 2 -H 2 O and NAD + -NADH, you subtract -0.32 from 0.82. This clearly results in a larger number than 0.82 because you subtract a negative, meaning that you add. With the example in the homework, FAD/FADH 2 has a slightly positive redox [potential (+0.031). It is still more negative than O 2 , but you subtract this positive number from the redox potential of O 2 , making a smaller number. The book lists five different types of electron carriers found in the electron transport chain. The key thing is that all have centers of some sort that are able to be oxidized and reduced. Some have iron centers, others copper, and some are organic (FAD and FMN or ubiquinone). The carriers are located in the inner mitochondrial membrane, arranged so than electrons flow between them. On a redox potential scale, moving electrons from NADH to O 2 involves movement to increasingly more positive redox potential pairs. This releases energy. At three steps, there is a significant energy release, and that energy is transformed into a proton gradient. Figure 5-15 illustrates how the sequence of steps in the electron transport chain were worked out using inhibitors. The complexes that make up the electron transport chain all consist of multiple proteins. Note that most are encoded in the nucleus, rather than the mitochondrion. Figure 5-18 illustrates an experiment that demonstrates cytochrome oxidase is a proton pump.
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Final Review Sheet – Week 7 Sample Questions 1. Separating the mitochondrial processes of TCA cycle, electron transport and oxidative posphorylation, where does each occur (in what compartment)? Where is the DNA located? TCA cycle is in the matrix, electron transport and oxidative phosphorylation in the inner membrane. The DNA (as well as ribosomes, etc.) is in the matrix. 2. Ubiquinone is an intermediate in the electron transport chain, the redox potential is : Calculate the G o ' for passing electrons from ubiquinone to oxygen. 3.
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This test prep was uploaded on 04/08/2008 for the course BIOL 301 taught by Professor Tepperman during the Winter '08 term at University of Cincinnati.

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Week 7 Review Sheet answers - Final Review Sheet Week 7...

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