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List four possible metabolic fates for pyruvate in a mammalian cell. Indicate the type of reaction that occurs. What additional reaction occurs in yeast?

Describe the five reactions of the pyruvate dehydrogenase multienzyme complex.

Which one of the five steps of the pyruvate dehydrogenase complex reaction is most likely to be metabolically irreversible? Explain.

Some human brain cancer cells contain a mutated form of isocitrate dehydrogenase that has lost its normal activity and instead catalyzes the NADP⁺-dependent reduction of the carbonyl group of α-ketoglutarate. Draw the structure of the reaction product.