Proteins

All proteins contain the

• Same 20 amino acids

• Different amino acids

• 300 Amino acids occurring in nature

• Only a few amino acids

The optically inactive amino acid is

• Glycine

• Serine

• Threonine

• Valine

Sulphur containing amino acid is

• Methionine

• Leucine

• Valine

• Asparagine

An example of sulphur containing amino acid is

• 2-Amino-3-mercaptopropanoic acid

• 2-Amino-3-methylbutanoic acid

• 2-Amino-3-hydroxypropanoic acid

• Amino acetic acid

All the following are sulphur containing amino acids found in proteins except

• Cysteine

• Cystine

• Methionine

• Threonine

An aromatic amino acid is

• Lysine

• Tyrosine

• Taurine

• Arginine

Amino acid with side chain containing basic groups is

• 2-Amino 5-guanidovaleric acid

• 2-Pyrrolidine carboxylic acid

• 2-Amino 3-mercaptopropanoic acid

• 2-Amino propanoic acid

An essential amino acid in man is

• Aspartate

• Tyrosine

• Methionine

• Serine

Non essential amino acids

• Are not components of tissue proteins

• May be synthesized in the body from essential

  amino acids

• Have no role in the metabolism

• May be synthesized in the body in diseased

  states

Which one of the following is semiessential amino acid for humans?

• Valine

• Arginine

• Lysine

• Tyrosine