Which of the following statements about catabolism of body proteins during starvation is correct?
A) The breakdown of proteins occurs spontaneously, without the need for enzyme catalysis.
B) The amino acids resulting from protein breakdown are either reused as such or are deaminated and their carbon skeletons used as a source of energy.
C) The first amino acids to be catabolized are derived from the protein storage depot in liver.
D) The amino acids derived are used primarily for synthesis of fatty acids.
E) The initial steps in the process involve cleavage of the amino acid side chains from polypeptides.

Question

Quizplus · Accepted Answer

During starvation, the body breaks down proteins to obtain amino acids, which can then be either reused for protein synthesis or deaminated and their carbon skeletons used as a source of energy. This process is catalyzed by enzymes and does not occur spontaneously. The first amino acids to be catabolized are not necessarily derived from the protein storage depot in liver, and the amino acids derived are not primarily used for synthesis of fatty acids. The initial steps in the process involve the removal of nitrogen from the amino acid, which is then excreted as urea.

Which of the Following Statements About Catabolism of Body Proteins