Question

Protein catabolism is accomplished by cleaving or transforming amino acids into constituent molecules of

a. glycolysis
b. oxidative phosphorylation
c. the amino acid ketoglutarate cycle
d. the citric acid cycle
e. beta oxidation"

Answer 1

Protein catabolism refers to the process where proteins are broken down, and their amino acids are converted into molecules that can enter the citric acid cycle for energy production after removing their amino groups.

Step-by-step explanation:

Protein catabolism is the process by which proteins are broken down into their constituent amino acids. During periods of excess amino acids or starvation, some of these amino acids are directed into pathways for energy production. After transamination, where the amino group is removed, the remaining α-keto acid is catabolized through pathways unique to each amino acid, often resulting in intermediates that enter the citric acid cycle, also known as the Krebs cycle. For instance, phenylalanine is degraded into fumarate, which is a Krebs cycle intermediate, and acetoacetate, which must be converted into acetyl-CoA before entering the cycle. The liver, responsible for much of amino acid metabolism, converts the removed amino groups into ammonia, which is further processed into urea and excreted from the body.