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Cell Biology

1. How do evolutionary biologist explain why there are two different ways of handling the pyruvate produced from glycolysis? Be sure to relate your answer to the nature of the Earth 3.5 billion years ago.

2. Explain at a biochemical level how wine is made and compare it to your activity of rapidly opening and closing your hand.

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1. How do evolutionary biologist explain why there are two different ways of handling the pyruvate produced from glycolysis? Be sure to relate your answer to the nature of the Earth 3.5 billion years ago.

The 2 different ways of handling pyruvate are distinguished by the amount of oxygen available. When there is sufficient oxygen, pyruvic acid is converted into acetyl-coenzyme A, which is the main input for a series of reactions known as the Krebs cycle. Pyruvate is also converted to oxaloacetate by an anaplerotic reaction and then further broken down to carbon dioxide. This is aerobic respiration and is also known as the citric acid cycle.
If the oxygen is not sufficient, the acid is broken down anaerobically, creating lactic acid in animals and ethanol in plants. Pyruvate from glycolysis is converted by anaerobic respiration to lactate using the enzyme lactate dehydrogenase and the coenzyme NADH in ...

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