In the aerobic metabolism of proteins by chemoheterotrophs (e. g., E. coli and you):. A. Proteins are broken down into smaller peptides and eventually into amino acids by proteases (peptidases).
B. Certain amino acids may be converted to pyruvate.
C. Certain amino acids may be converted to intermediates (e. g. oxaloacetate) of the Krebs cycle.
D. Certain amino acids may be converted to acetyl-CoA.
E. All of the above are true.