Figure 7.1
-Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the citric acid cycle. Which intermediate could directly supply the carbon skeleton for synthesis of a five-carbon amino acid (see Figure 7.1)?

Question

Quizplus · Accepted Answer

α-ketoglutarate is a five-carbon intermediate of the citric acid cycle and can directly supply the carbon skeleton for synthesis of a five-carbon amino acid. Succinate is a four-carbon intermediate, malate is a four-carbon intermediate that can be converted to pyruvate or oxaloacetate but not directly to a five-carbon amino acid, citrate is a six-carbon intermediate, and isocitrate is a five-carbon intermediate but does not supply the carbon skeleton for amino acid biosynthesis.

Figure 7.1 -Carbon Skeletons for Amino Acid Biosynthesis Are Supplied by Intermediates