What will happen to the carbon skeleton of the deaminated amino acid when excessive protein and calories are consumed?

Question

A. It is metabolized by the liver to urea

B. They will be metabolized to fat

c. They will be metabolized to ketones

Answer 1

Interesting question, and a little tricky to answer.

The first step in amino acid metabolism is deamination and conversion of the amine to urea. This takes place in the liver. So, (A) would be correct, except the question asks about the "carbon skeleton" and not the intact amino acid. So, we will eliminate (A) as the correct answer.

Now, between choices (B) and (C), they actually can both be correct. If the amino acid skeleton is used in the ketogenic pathway, then ketones are produced, but these can then go on to be used in fatty acid synthesis. So, the "best" answer would probably be (C)

Answer 2

The answer is C. they will be metabolized to ketones. Carbon skeleton after deamination gives rise to ketones acetyle CoAs,  Pyruvate, which may further enter the krebs cycle to form Glucose.