Usefulness of Fermentation

Usefulness of Fermentation - Today, nearly all organisms...

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Usefulness of Fermentation Anaerobic exercise During vigorous exercise, oxygen is consumed faster than it is needed. Additional ATP energy is provided to the muscles by glycolysis and the result is a buildup of lactate in the muscles. When lactate builds up, the blood pH drops and the muscles fatigue. At rest, lactate is converted back to pyruvate (the oxygen debt is repaid). This is why you continue to breathe hard after you have finished running or rapid stair climbing. Yeast Yeast produce alcohol which accumulates in their environment. As the concentration of alcohol in their environment increases, it becomes more and more toxic to them. Beer and wine have a maximum alcohol concentration because a higher concentration will kill the yeast cells. Evolution of Cellular Respiration Early cells probably fermented organic molecules in the oceans.
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Unformatted text preview: Today, nearly all organisms show some form of fermentation which indicates that it evolved early in evolutionary history. Evolution typically operates by building upon or adding to what is already there. Aerobic respiration appears to have been added to fermentation. Summary Glycolysis Two ATP molecules are used to phosphorylate and activate glucose . Two hydrogen atoms are removed by NAD + forming 2 NADH. Four ATP molecules are produced by substrate-level phosphorylation . The net yield of ATP is two; two are used and four are produced. Fermentation Fermentation is needed to regenerate NAD + from NADH so that at least some ATP can be made in glycolysis. Electrons from NADH are added to pyruvate ( reduction ) to produce alcohol (plants, yeast) or lactate (animals, bacteria)...
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