Metabolism Of Amino Acids

Question 1

_ and _ are the two non-essential amino acids that require an essential amino acid for their synthesis

Answer 1

Tyrosine and cysteine
(Phenylalanine for tyrosine)
(Methionine for cysteine)

Question 2

Name the four proteins produced from glucose through components of the glycolytic pathway

Answer 2

Serine, cysteine, glycine and alanine

Question 3

Ketoglutarate is the precursor for the synthesis of _, _, _ and _

Answer 3

Glutamate, glutamine, proline and arginine

Question 4

Oxaloacetate provides carbon for the synthesis of _ and _

Answer 4

Aspartate and asparagine

Question 5

Synthesis of glutamate is formed by the _

Answer 5

Reductive animation of a-ketoglutarate

Question 6

Synthesis of proline

Answer 6

3 step cyclization reaction of glutamate
1) a) glutamate kinase hydrolysis of ATP to ADP and Pi to provide energy for the initial reduction
b) glutamate dehydrogenase reduction of glutamate to a semi-aldehyde

2) spontaneous cyclization of semi-aldehyde to pyroline-5-carboxylate

3) reduction of pyroline-5-carboxylate to proline by a NADPH dependent proline carboxylate reductase

Question 7

Synthesis of aspartate

Answer 7

Transamination product of Oxaloacetate with glutamate being the NH4+ donor. It is catalases by aspartate aminotransferase (AST)

Question 8

List the ways by which amino acid biosynthesis is regulated

Answer 8

1) sequential feedback inhibition
2) enzyme multiplicity
3) cumulated feedback inhibition
4) concerted feedback inhibition

Question 9

What are the three conditions during which amino acid is degraded

Answer 9

1) excess amino acid than required for synthesis of important biomolecules in the body
2) during starvation, they are degraded for glucose production
3) Amon acids not needed during protein turnover for synthesis are degraded

Question 10

_ is the only exclusively ketogenic amino acid

Answer 10

Leucine