Question

Amino acid catabolism involves the breakdown of 20 amino acids all of which contain nitrogen but have different carbon skeletons. What overall strategy is used to deal with the variations in C-fragments that are produced? Convert the carbon skeletons into nucleotides Convert the amino groups into nucleotides Convert the carbon skeletons into glucose Convert the carbon skeletons into Acetyl CoA

Answer 1

The overall strategy employed in the catabolism of the carbon skeletons of the 20 amino acids is conversion to citric acid intermediates such as acetyl-CoA

Step-by-step explanation:

The breakdown of the different carbon skeletons of the 20 amino acids is strategically channelled towards the citric acid cycle. Six major products are obtained in the catabolism of the carbon chain of amino acids and these products all enter the citrc acid cycle. The six major products are acetyl-CoA, α-ketoglutarate, succinyl-CoA, fumarate, oxaloacetate and pyruvate.

The amino acids that are broken down completely into acetoacetyl-CoA and/or acetyl-CoA are said to be ketogenic since they yield ketone bodies in the liver.

The amino acids that are broken down into α-ketoglutarate, succinyl-CoA, fumarate, oxaloacetate and pyruvate can be converted to glucose and glycogen and are said to be glucogenic. Pyruvate can further be converted to either acetyl-CoA or oxaloacetate. Some amino acids though are both ketogenic and glucogenic, e.g. tryptophan, threonine.