Which of the following statements regarding amino acid metabolism is true?

Question

• When broken down in the mitochondrion, the energy yield of an amino acid is negligible.
• The removal of the amino group is the first step in amino acid catabolism.
• The body synthesizes all of the 10 essential amino acids.
• Liver cells must break down urea, a toxic compound

Answer 1

The true statement regarding amino acid metabolism is:

The removal of the amino group is the first step in amino acid catabolism.

This process is known as deamination, where the amino group is removed from the amino acid, leading to the formation of ammonia and a carbon skeleton that can enter various metabolic pathways.

The other statements are not accurate:

• The energy yield of amino acids can be significant when metabolized, as they can be converted into glucose or fatty acids.
• The body cannot synthesize the essential amino acids; they must be obtained from the diet.
• Liver cells do not break down urea; instead, they synthesize urea from ammonia in the urea cycle to detoxify it.