Use your knowledge of amino acids for energy metabolism to select the term that best completes each description. Glucose cannot be made when amino acids are converted to___ . In the TCA cycle, some amino acids enter directly and, therefore, can continue in the cycle to generate energy and_ . When is available, the body can use and glycerol to make some non-essential amino acids.

Acetyl-CoA is a molecule known to be part of different reactions during carbohydrate, protein, and lipid metabolism. Pyruvate (also known as pyruvic acid) is a molecule whose decarboxylation produces acetyl-CoA. Glucose cannot be synthesized when amino acids are converted to Acetyl CoA because this molecule (Acetyl CoA) cannot be converted back to pyruvate. The citric acid cycle (CAC), also known as the tricarboxylic acid (TCA) cycle, is a group of biochemical reactions that release energy by oxidation of acetyl-CoA obtained from sources such as proteins, carbohydrates and fats. During amino acid metabolism, glucogenic amino acids and TCA intermediates can be converted into glucose through gluconeogenesis.