Phenylalanine, threonine and tryptophan all are glucogenic as well as ketogenic amino acids.

This option is correct because liver is the main site for transamination and transamination reactions are catalysed by aminotransferases (transaminases).

This option is correct because Sanger’s reagent is use for determining the N-terminal amino acid in peptide chains, in particular insulin.

α-ketoglutarate, Succinyl-CoA, Fumarate and Oxaloacetate all are glucogenic intermediates (form glucose).

Glutamate dehydrogenase (GLDH) is an anaerobic dehydrogenase.

Desulfhydrase deaminates sulphur-containing amino acids, e.g. cysteine and cystine.

Aspartate acts as metabolic precursor to asparagine, methionine, threonine and lysine.

Both dehydratase and desulfhydrase need pyrindoxal phosphate as coenzyme.

In dopaminergic cells in the brain, tyrosine is converted to L-DOPA by the enzyme tyrosine hydroxylase (TH). TH is the rate-limiting enzyme involved in the synthesis of the neurotransmitter dopamine. Dopamine can then be converted into norepinephrine and epinephrine.

Ornithine and Citrulline are non-protein amino acids.

A significant amount of metabolic energy can come from amino acid metabolism, particularly under conditions of starvation. Amino acids that are metabolized to produce acetyl-CoA and acetoacetate are called ketogenic amino acids. In humans, two amino acids are exclusively ketogenic: Leucine and Lysine.

Millon’s test is for identification of tyrosine.

Both serine and threonine have -OH groups; so they can undergo phosphorylation.

Alanine is most commonly produced by reductive amination of pyruvate. α-ketoglutarate (also known as oxoglutarate) is a precursor to glutamine. Ribose 5-phosphate is a key precursor to histidine. Glycerate 3-phosphate is a precursor to serine.

Aromatic amino acids can be detected by Xanthoproteic reaction. Edman’s reaction can be used to determine the amino acid sequence of a protein. Millon’s test is for identification of L-2-Amino-3-(4-hydroxyphenyl)propanoic acid. Hopkins-Cole test is for identification of 2-Amino-3-(1H-indol-3-yl)propanoic acid.