7.2 Glucogenic amino acids serve as carbon sources for gluconeogenesis
So far, we have seen that the TCA serves to completely degrade acetyl-CoA. In addition to this degradative function, the TCA also serves to 'collect' the carbon skeletons from several amino acids, which can be converted into different TCA intermediates (Figure 7-1) and from there to oxaloacetate. Other amino acids can be converted to pyruvate. Since pyruvate can be converted to oxaloacetate in turn, we can summarize that all amino acids that can be converted to any intermediate of the citric acid cycle or to pyruvate can be utilized for gluconeogenesis. Such amino acids are glucogenic amino acids.
Amino acids that cannot be converted to glucose but can be converted to 'ketone bodies' instead are referred to as ketogenic. We will learn more about both ketone bodies and amino acid degradation later.