2. Fermentation and Control of Cellular Respiration AP Biology Unit 4

3. Fermentation Occurs when there is no oxygen available allows some cells to produce ATP without the use of oxygen –ATP yield would be lower, though. Do you know why? –Only glycolysis is carried out– only 2 ATP produced.

4. Fermentation Overview Fermentation allows glycolysis to continue by producing the reactants it needs – NAD+ Where is the NAD+ usually regenerated from? –Electron transport chain– after the NADH drops off its electrons.

5. Types of Fermentation Different organisms will carry out different fermentation processes: –Alcoholic Fermentation –Lactic Acid Fermentation Images taken without permission from http://www.the-voyage.com/kids_new/images/illustrations/find_out/bread_300.jpg and http://podiatry.curtin.edu.au/encyclopedia/running/running.JPGhttp://www.the-voyage.com/kids_new/images/illustrations/find_out/bread_300.jpg

6. Alcoholic Fermentation Occurs in yeast and many bacteria End products are ethanol and NAD+ Used to make bread, wine, beer

7. Lactic Acid Fermentation Occurs in certain fungi and bacteria, and humans End products are lactate and NAD+ Lactate is eventually converted back to pyruvate in the liver

8. Aerobic vs. Anaerobic Aerobic = requires oxygen Anaerobic = does not require oxygen When there is no oxygen present, fermentation (and glycolysis) occurs

9. Versatility Glucose is not the only fuel that can be used in cellular respiration Other biomolecules can be converted into intermediates and used in cellular respiration

10. Control of Cellular Respiration Feedback mechanisms help regulate cellular respiration –Ex. Feedback inhibition –Phosphofructokinase (PFK) is the major enzyme in glycolysis that is controlled –ATP, Citrate inhibits –ADP, AMP stimulates it