Description : Melatonin is synthesised from (A) Phenylalanine (B) Tyrosine (C) Tryptophan (D) None of these
Last Answer : Answer : C
Description : Niacin can be synthesised in human beings from (A) Histidine (B) Phenylalanine (C) Tyrosine (D) Tryptophan
Last Answer : Answer : D
Last Answer : (D) Tryptophan
Description : .Khorana first deciphered the triplet codons of (a) serine and isoleucine (b) cysteine and valine (c) tyrosine and tryptophan (d) phenylalanine and methinonine.
Last Answer : (a) serine and isoleucine
Description : Khorana first deciphered the triplet codons of (a) serine and isoleucine (b) cysteine and valine (c) tyrosine and tryptophan (d) phenylalanine and methinonine
Last Answer : (b) cysteine and valine
Description : Seratonin is derived in the body from the following amino acid: (A) Phenylalanine (B) Histidine (C) Tryptophan (D) Serine
Description : In mammalian tissues serine can be a biosynthetic precursor of (A) Methionine (B) Glycine (C) Tryptophan (D) Phenylalanine
Last Answer : Answer : B
Description : Activation or inactivation of certain key regulatory enzymes is accomplished by covalent modification of the amino acid: (A) Tyrosine (B) Phenylalanine (C) Lysine (D) Serine
Description : The limiting amino acid of rice is (A) Lysine (B) Tryptophan (C) Phenylalanine (D) Tyrosine
Last Answer : Answer : A
Description : Million-Nasse’s reaction is specific for the amino acid: (A) Tryptophan (B) Tyrosine (C) Phenylalanine (D) Arginine
Description : The biosynthesis of both Catecholamine and serotonin require (A) Tyrosine hydroxylase (B) N-methyl transferase (C) Aromatic amino acid decarboxylase (D) Tryptophan pyrrolase
Description : Branched chain amino acids are (A) Cysteine and cystine (B) Tyrosine and Tryptophan (C) Glycine and Serine (D) Valine, Leucine and Isoleucine
Description : All the following are true about phenylketonuria except (A) Deficiency of phenylalanine hydroxylase (B) Mental retardation (C) Increased urinary excretion of p-hydroxyphenyl pyruvic acid (D) Decrease serotonin formation
Description : In A chain of the insulin molecule the Nterminal amino acid is (A) Glycine (B) Valine (C) Serine (D) Phenylalanine
Description : The amino acid containing an indole ring: (A) Tryptophan (B) Arginine (C) Threonine (D) Phenylalanine
Description : Pulses are rich in (A) Lysine (B) Methionine (C) Tryptophan (D) Phenylalanine
Description : The lone pair of electrons at one of the ring nitrogens in the given amino acid makes a potential ligand, which is important in binding the iron atoms in hemoglobin: (A) Tryptophan (B) Threonine (C) Histidine (D) Serine
Description : All amino acids are optically active except (A) Glycine (B) Serine (C) Threonine (D) Tryptophan
Description : Tyrosine hydroxylase is inhibited by (A) Catecholamines (B) α−Methyldopa (C) Phenylalanine (D) Vanillyl mandelic acid
Description : The rate limiting step in catecholamine synthesis is catalysed by (A) Phenylalanine hydroxylase (B) Tyrosine hydroxylase (C) Dopa decarboxylase (D) Phenylethanolamine N-methyl transferase
Description : Thyroid hormones are synthesized by the iodination of the amino acid: (A) Glycine (B) Phenylalanine (C) Alanine (D) Tyrosine
Description : A characteristic of pheochromocytoma is elevated urinary excretion of (A) Dopamine (B) Tyrosine (C) Vinylmandelic acid (D) Phenylalanine
Description : For Catecholamine biosynthesis the rate limiting enzyme is (A) DOPA decarboxylase (B) DOPAMINE β-hydroxylase (C) Tyrosine hydroxylase (D) Phenylalanine hydroxylase
Description : Neonatal tyrosinemia is due to deficiency of the enzyme: (A) p-Hydroxyphenylpyruvate hydroxylase (B) Fumarylacetoacetate hydrolase (C) Phenylalanine hydroxylase (D) Tyrosine dehydrogenase
Description : Albinism is due to deficiency of the enzyme: (A) Phenylalanine hydroxylase (B) Tyrosinase (C) p-Hydroxyphenylpyruvic acid oxidase (D) Tyrosine dehydrogenase
Description : Richner-Hanhart syndrome is due to defect in (A) Tyrosinase (B) Phenylalanine hydroxylase (C) Hepatic tyrosine transaminase (D) Fumarylacetoacetate hydrolase
Description : Million’s test is positive for (A) Phenylalanine (B) Glycine (C) Tyrosine (D) Proline
Description : Which one of the following is an essential amino acid? (A) Arginine (B) Tyrosine (C) Phenylalanine (D) Proline
Description : All the following statements about phenylketonuria are correct except (A) Phenylalanine cannot be converted into tyrosine (B) Urinary excretion of phenylpyruvate and phenyllactate is increased (C) It ... diet (D) It leads to decreased synthesis of thyroid hormones, catecholamines and melanin
Description : The rate limiting step in the biosynthesis of catecholamines is (A) Decarboxylation of dihydroxyphenylalanine (B) Hydroxylation of phenylalanine (C) Hydroxylation of tyrosine (D) Oxidation of dopamine
Description : Phenylalanine is the precursor of (A) L-DOPA (B) Histamine (C) Tyrosine (D) Throxine
Last Answer : C
Description : In carcinoid syndrome the argentaffin tissue of the abdominal cavity overproduce (A) Serotonin (B) Histamine (C) Tryptamine (D) Tyrosine
Description : Which of the following amino acid has been shown as one of the active site of phosphoglucomutase? (A) Lysine (B) Tyrosine (C) Serine (D) Histidine
Description : Small amount of urinary oxalates is contributed by the amino acid: (A) Glycine (B) Tyrosine (C) Alanine (D) Serine
Description : An essential amino acid in man is (A) Aspartate (B) Tyrosine (C) Methionine (D) Serine
Description : Homogentisic acid is formed from (A) Homoserine (B) Homocysteine (C) Tyrosine (D) Tryptophan
Description : Adrenalin is synthesized from (A) Adenine (B) Adenosine (C) Tyrosine (D) Tryptophan 230 MCQs IN BIOCHEMISTRY
Description : An amino acid used for the synthesis of thyroid hormone is (A) Tyrosine (B) Tryptophan (C) Histidine (D) Proline
Description : The proteins present in maize are deficient in (A) Lysine (B) Threonine (C) Tryptophan (D) Tyrosine
Description : Niacin is synthesized in the body from (A) Tryptophan (B) Tyrosine (C) Glutamate (D) Aspartate
Description : An amino acid that does not form an αhelix is (A) Asparagine (B) Tyrosine (C) Tryptophan (D) Proline
Description : Side chains of all following amino acids contain aromatic rings except (A) Phenyl alanine (B) Alanine (C) Tyrosine (D) Tryptophan
Description : The sparing action of methionine is (A) Tyrosine (B) Cystine (C) Arginine (D) Tryptophan
Description : Side chains of all amino acids contain aromatic rings except (A) Pheynl alanine (B) Alanine (C) Tyrosine (D) Tryptophan
Description : Xanthuric acid is an abnormal metabolite of (A) Xanthine (B) Uric acid (C) Tyrosine (D) Tryptophan
Description : Hopkins-Cole test is for identification of (A) Tyrosine (B) Tryptophan (C) Arginine (D) Cysteine
Description : Millon’s test is for identification of (A) Tyrosine (B) Tryptophan (C) Proline (D) Arginine
Description : The amino acid which gives yellow colour with Ninhydrin in paper chromatography is (A) Tyrosine (B) Proline (C) Tryptophan (D) Alanine
Description : Which among the following is a nutritionally essential amino acid for man ? (A) Alanine (B) Glycine (C) Tyrosine (D) Tryptophan
Description : An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan