Question

The carbon skeletons of which two amino acids directly enter metabolism at the level of pyruvate?

Answer 1

Alanine and Serine
The degradation of amino acid is to transform the carbon skeleton into metabolic intermediates that can be easily be oxidized by the citric acid cycle or converted into glucose. Both Alanine and serine provide substrate for ketone bodies gluconeogenesis. However, metabolism of alanine yields pyruvate directly by transamination