Question

Describe the two general metabolic fates of the carbon skeletons of amino acids.

Short answer

Two general metabolic fates of the carbon skeletons of amino acids are glucogenic amino acids and ketogenic amino acids.

Step-by-step solution

Degradation of amino acids.

Amino acids are degraded to compounds that can be metabolized to ${\mathbf{\text{CO}}}_{\mathbf{\text{2}}}$ and ${\mathbf{\text{H}}}_{\mathbf{\text{2}}}\mathbf{\text{O}}$ or used in gluconeogenesis. The amino acids can be divided into groups based on their catabolic pathways.

Step 2: Glucogenic amino acids.

The glucogenic amino acid is degraded to pyruvate,α-ketoglutarate, succinyl-CoA, fumarate, or oxaloacetateand is a glucose precursor.

Step 3: Ketogenic amino acids.  

The ketogenic amino acids are broken down to acetyl-CoA or acetoacetate and can be converted to fatty acids or ketone bodies.