Chapter 9

Focus Questions 1) What is the purpose of cell respiration? 2) What is the difference between aerobic and anaerobic respiration? 3) What is fermentation and what are the possible products? 4) What is glycolysis? 5) What occurs during the Krebs cycle? 6) How is ATP made from the electron transport chain?

I) Principals of energy harvest A) Catabolic pathways 1) a metabolic pathway that releases energy by breaking bonds a) fermentation: without oxygen b) respiration: with O2

2) an organism’s goal is to transfer this stored energy into ATP

3) ATP synthesis driven by redox reactions a) LEO says GER lose e-, oxidized gain e-, reduced b) example:

4) NAD+ as an oxidizing agent(becomes reduced) a) this transfers high energy electrons throughout the process of respiration

II) Cell Respiration A) Glycolysis 1) breakdown of glucose into 2 pyruvate molecules

2) 2 ATP are required to start this process

3) As it continues, H+ and e- are pulled off and given to NAD+(to become reduced)

4) Final products are: 2 ATP 2 NADH 2 pyruvic acid(which immediately ionize into pyruvate and H+) tch?v=3GTjQTqUuOw tch?v=6JGXayUyNVw&feat ure=related

B) Krebs 1) Pyruvate enters the matrix of the mitochondria and loses a carboxyl group, which is replaced by coenzyme A. Now called acetyl CoA a) now gain an NADH

2) Acetyl CoA officially enters the Krebs cycle by binding to Oxaloacetate

3) This goes along an enzymatic pathway that snips C, and O off, creating CO2, NADH, and FADH2

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4) Final products by the end of glycolysis and Krebs are: Glycolysis: 2 ATP 2 NADH+ Krebs 8 NADH+ 2 FADH2 2 ATP 6 CO2

C) Electron Transport

1) Components of ETC

2) Movement of e- and generation of H+ gradient(electrochemical gradient)

3) Chemiosmosis

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III) Fermentation Facultative anaerobes:

IV) Respiration extended A) Fuels other than glucose 1) Proteins a) must be broken down into individual amino acids, and then their amino group is removed by deamination

2) Fats: energy is stored in fatty acids. Beta oxidation breaks them down and sticks them in as acetyl CoA.

B) Feedback 1) Phosphofructokinase(PF K): major enzyme in glycolysis a) AMP is made from ADP, so high levels of AMP stimulate PFK. b) If energy is being produced, ATP and citrate inhibit PFK so too much isn’t made.