1. Cell Respiration II: Fermentation reactions During strenuous exercise or when O2 is unavailable or low in the environment, ATP production still needs to occur for life to continue. Fermentation reactions allow ATP to be produced and pyruvate (or its derivative) becomes the terminal electron acceptor freeing NAD coenzyme to recycle back to oxidizing (breaking down) food molecules

2. In fermentation, only 1 pathway functions  Glycolysis! Glycolysis typically produces: 2 ATP’s (Net) 2 NADH2 2 molecules of pyruvate Glycolysis does not require O2 The energy output of glycolysis is marginal as compared with aerobic respiration Pyruvate (or its derivative) serve as the terminal electron acceptor

3. In all cases, NAD+ has to be recycled back to the system to help oxidize more food to make ATP!!

4. Lactate fermentation occurs in many organisms including animals Alcohol fermentation generally occurs in fungi and bacteria