Amino Acid Metabolism and Biochemistry
Covers glucogenic and ketogenic amino acids, transamination, dehydrogenases, phosphorylation, metabolic precursors, and identification tests for amino acids. Suitable for biochemistry and GATE exam preparation.
Questions
Which of the following amino acids are both glucogenic and ketogenic?
- Glycine
- Phenylalanine
- Threonine
- Proline
- Tryptophan
- 1, 2 and 4
- 1, 4 and 5
- 2, 3 and 4
- 2, 3 and 5
- 3, 4 and 5
Which of the following statements are true regarding transamination?
P. Transamination means transfer of amide nitrogen from a donor molecule to an acceptor molecule.
Q. Liver is the main site for transamination.
R. Transamination reactions are irreversible.
S. Transamination reactions are catalysed by aminotransferases.
- P and Q
- P and R
- P and S
- Q and R
- Q and S
For the identification of which of the following entities is Sanger’s reagent?
- N-terminal of a peptide chain
- C-terminal of a peptide chain
- Side chain of amino acid
- Molecular weight of the peptide chain
- Number of amino acids in the peptide chain
Which among the following are glucogenic intermediates?
- Pyruvate
- α-ketoglutarate
- Succinyl-CoA
- Fumarate
- Oxaloacetate
- Acetyl-CoA
- Acetoacetate
- 1, 2, 3 and 4
- 1, 3, 5 and 7
- 2, 3 4 and 5
- 3, 4, 5 and 6
- 4, 5, 6 and 7
Which of the following is/are example(s) of anaerobic dehydrogenases?
- LAAO
- DAAO
- GLDH
- Only 1
- Only 2
- Only 3
- 1 and 2
- 2 and 3
Desulfhydrase deaminates
- cystine
- serine
- threonine
- Only 1
- Only 2
- Only 3
- 1 and 2
- 2 and 3
Which of the following amino acids can act as metabolic precursor for synthesis of methionine and lysine?
- Aspartate
- Glutamate
- Phenylalanine
- Serine
- Threonine
Which of the following enzymes need pyrindoxal phosphate as coenzyme?
P. D-amino acid oxidase
Q. Dehydratase
R. Desulfhydrase
S. Glutamate dehydrogenase
- P and Q
- P and R
- P and S
- Q and R
- Q and S
Which of the following amino acids acts as precursor to hormones epinephrine, norepinephrine and dopamine?
- Tyrosine
- Threonine
- Tryptophan
- Proline
- None of these
Which of the following is a pair of non-protein amino acids?
- Ornithine and Citrulline
- Glycine and Tyrosine
- Valine and Arginine
- Ornithine and Tyrosine
- Arginine and Citrulline
Which of the following is a pair of exclusively ketogenic amino acids?
- Leucine and Isoleucine
- Leucine and Lysine
- Lysine and Tyrosine
- Isoleucine and Lysine
- Leucine and Tyrosine
Which of the following tests is used in identification of tyrosine?
- Xanthoproteic reaction
- Millon’s test
- Hopkins-Cole test
- Edman’s reaction
- Hippuric acid test
Which of the following amino acids undergo(es) phosphorylation?
- Serine
- Threonine
- Proline
- Only 1
- Only 2
- Only 3
- 1 and 2
- 2 and 3
Match the following amino acids with their metabolic precursors and select the correct option.
| Amino acid | Metabolic precursor |
| A. Alanine | 1. α-ketoglutarate |
| B. Glutamine | 2. Pyruvate |
| C. Histidine | 3. 3-phosphoglycerate |
| D. Serine | 4. Ribose 5-phosphate |
- A - 4, B - 3, C - 2, D - 1
- A - 2, B - 1, C - 3, D - 4
- A - 2, B - 1, C - 4, D - 3
- A - 3, B - 2, C - 4, D - 1
- A - 1, B - 2, C - 3, D - 4
Match the following:
| Column – I | Column – II |
| P. Xanthoproteic reaction | 1. Identification of 2-Amino-3-(1H-indol-3-yl)propanoic acid |
| Q. Edman’s reaction | 2. Determination of the amino acid sequence of a protein |
| R. Millon’s test | 3. Identification of L-2-Amino-3-(4-hydroxyphenyl)propanoic acid |
| S. Hopkins-Cole test | 4. Detection of aromatic amino acids |
- P – 1, Q – 3, R – 2, S – 4
- P – 1, Q – 2, R – 4, S – 3
- P – 2, Q – 1, R – 4, S – 3
- P – 4, Q – 2, R – 3, S – 1
- P – 4, Q – 3, R – 2, S – 1