Question

Many amino acids are broken down into acetyl CoA, just like fatty acids. However, we typically

consider amino acids a lower energy fuel source than fatty acids. Why is this? Hint: there are actually

two reasons, one related to the amount of energy that can hypothetically be obtained from breakdown of

amino acids, and one related to the nitrogen atom(s).

Answer 1

Ans: Amino acids are considered as a lower energy fuel source than fatty acids due to below-mentioned reasons-

1. Complete oxidation of 1 fatty acid molecule generates over a hundred ATP molecules while amino acid oxidation results in almost 40 ATP molecules.

2. An amino skeleton is divided into carbon chain, nitrogen atoms, and -NH2 group. The nitrogen of amino groups can't be used for energy production and must be removed using different pathways.

Amino acid carbon skeleton is converted to fatty acid and doesn't have nitrogen.