Amino Acid Synthesis

Question 1

Nonessential amino acids

Answer 1

Ala

Asparagine

Aspartate

Glu

Ser

Question 2

Conditionally essential amino acids

Answer 2

Arg

Cys

Glutamine

Gly

Pro

Tyr

Question 3

Essential amino acids

Answer 3

His

Isoleucine

Leucine

Lysine

Met

Phenyl

Thr

Tryptophan

Valine

Question 4

Gylcolytic precursors for amino acid carbon skeletons

Answer 4

3-phosphogylcerate

• Ser
• Gly
• Cys

Pyruvate
- Ala

Question 5

CAC precursors for amino acids

Answer 5

A-KG

• Glu
• Gln
• Pro
• Arg

OAA

• Asp
• Asn

Question 6

What precursors are amino acids not made from in humans!!

Answer 6

Phosphoenolpyruvate

PPP precursors

Question 7

A-KG as a precursor —> ?

Answer 7

A-KG —> glutamate —> (Gln, Pro, or Arg)

Question 8

What two ways can a-KG —> glutamate

Answer 8

1. Aspartate aminotransferase (AST)

2. Glutamate dehydrogenase (reverse reaction)

Question 9

OAA —> ? Amino acid —> ? Amino acids?

Answer 9

OAA —> aspartate

Aspartate —> asparagine (Asparagine synthase)

Asp —> Asn, Met, Lys, Thr (bacteria…since last 3 are essential amino acids)

Question 10

Pyruvate —> amino acids?

Answer 10

Pyruvate —> alaine (ALT, humans)

Pyruvate —> Ala, Val, Leu, Isoleucine (bacteria, last 3 are essential)

Question 11

3-phosphogylcerate as a precursor

Answer 11

Glycolytic intermediate

—> serine —> glycine or cysteine

3-phosphoglycerate —> Ser
….requires oxidation reaction…then a transamination reaction….then a removal of a phosphate

To make glycine….need H4folate

To make cysteine…serine is condenses with HC —> then broken to make Cysteine and a-ketobutyrate