Oxidative Deamination Explained: From Glutamate To Ammonia

Oxidative Deamination Explained: From Glutamate To Ammonia

Question 1. Give one example each for transamination and deamination of amino acids.
Answer:

Example of transamination reaction:

• Transfer of amino group to coenzyme pyridoxal phosphate to form pyridoxamine phosphate

Example of deamination of amino acids:

1. Oxidative deamination

• Catalyzation of glutamate by glutamate dehydrogenase to liberate ammonia

2. Non-oxidative deamination

• Deamination of hydroxy amino acids by PLP-dependent hydrates

Question 2. Oxidative deamination
Answer:

It is the liberation of free ammonia from the amino group of amino acids along with oxidation

Example:

• Amino acids oxidases act on respective amino acids to produce a ketoacid and ammonia.

Question 3. Classify amino acids based on their nutritional importance and give two examples of each.
Answer:

1. Essential amino acids

• They cannot be synthesized by the body
• Example: valine, leucine, lysine

2. Semi-essential amino acids

• Can be synthesized by adults but not by children
• Examples: arginine, histidine

3. Nonessential amino acids

• They are synthesized in the body
• Examples: glycine, serine, aspartate, alanine

Question 4. Define isoelectric pH and denaturation.
Answer:

Isoelectric pH:

• It is defined as the pH at which a molecule exists as a Twitter ion and carries no net charge.
• The molecule is neutral with
  • Minimum solubility
  • Maximum precipitability
  • Least buffering capacity
• Value
  • Casein – 4.6
  • Albumin – 4.7
  • Haemoglobin – 6.7

Denaturation of proteins:

• It is the phenomenon of the disorganization of native protein structures.

Question 5. Write the enzyme defect and the metabolite excreted in the urine of the following disorder

1. Phenylketonuria
2. Alkaptonuria
3. Albinism

Answer:

Question 6. Name the various products formed from glycine
Answer:

1. Products formed from glycine:
2. NH4
3. Carbon dioxide
4. One carbon fragment as N5,
5. N10 methylene THF.