Lec 2: AST/ALT

Question 1

A group of enzymes that catalyze the interconversion of amino acids to 2-oxo acids by transfer of amino group

Answer 1

Aminotransferase
or
Transaminase

Question 2

“the reversible transfer of an -NH₂ from amino acid to keto acid”

The reaction has an equilibrium constant of ___.

Answer 2

Equilibrium constant of 1

Question 3

1. What specific amino acid does ALT act on?
2. What keto acid is the specific amino acceptor?
3. After ALT acts on #1, it becomes into ___.
4. After ALT acts on the amino acid, what does a-ketoglutarate become into?
5. What cycle does #3 enter?

Answer 3

1. L-alanine
2. a-ketoglutarate
3. Pyruvate
4. L-glutamate
5. Citric acid cycle / TCA / Kreb’s cycle

Question 4

What amino acid does AST specifically act on?

Answer 4

L-aspartate

Question 5

In AST, what is the specific amino acceptor?

Answer 5

a-ketoglutarate

Question 6

What are the products of this reaction:

L-aspartate + a-ketoglutarate
—(AST)—>

Answer 6

Oxaloacetate (keto acid)

L-glutamate (new amino acid)

Question 7

1. The first people who recognized the enzymatic transamination
2. How

Answer 7

1. Braunstein & Kritzman
2. They demonstrated that pigeon breast muscle catalyzed the formation of glutamate from 2-oxoglutarate and several amino acids