More Amino Acid Catabolism

Question 1

What are the intermediate products of the breakdown of the amino acid carbon skeletons and what are they used for?

Answer 1

The products are:
4 TCA cycle intermediates
pyruvate
acetyl-CoA
acetoacetate

They are used for:

1. gluconeogenesis
2. production of energy via the TCA cycle (then oxidative phosphorylation)

Question 2

How does the body obtain non-essential amino acids?

Answer 2

It makes them from metabolic intermediates.

Question 3

How does the body obtain Ala?

Answer 3

It synthesizes it from pyruvate.

Question 4

How does the body obtain Glu?

Answer 4

It synthesizes it from α-ketogluterate.

Question 5

How does the body obtain Asp?

Answer 5

It synthesizes it from oxaloacetate.

Question 6

How does the body obtain Arg?

Answer 6

It synthesizes it from argininosuccinate.

Question 7

How does the body obtain essential amino acids?

Answer 7

From the diet.

Question 8

What are gluconeogenic amino acids?

Answer 8

pyruvate or TCA cycle intermediates, can be used for synthesis of glucose (glycogen)

Question 9

What are ketogenic amino acids?

Answer 9

Those that when catabolized form ketone bodies or energy (via TCA / ox. phosph.) but NOT glucose

Question 10

Which amino acids are gluconeogenic and ketogenic?

Answer 10

Ile, Phe, Trp, Tyr

Question 11

Which amino acids are exclusively ketogenic?

Answer 11

Those that begin with the letter L: Lys, Leu