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
Last Answer : Answer : D
Description : Which among the following is a nutritionally essential amino acid for man? (A) Alanine (B) Glycine (C) Tyrosine (D) Isoleucine
Description : Which among the following is a nutritionally essential amino acid for man ? (A) Alanine (B) Glycine (C) Tyrosine (D) Tryptophan
Description : Small amount of urinary oxalates is contributed by the amino acid: (A) Glycine (B) Tyrosine (C) Alanine (D) Serine
Last Answer : Answer : A
Description : Million’s test is positive for (A) Phenylalanine (B) Glycine (C) Tyrosine (D) Proline
Last Answer : Answer : C
Description : Which of the following is the simplest amino acid? (a) Alanine (b) Asparagine (c) Glycine (d) Tyrosine
Last Answer : (c) Glycine
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 : Which one of the following is an essential amino acid? (A) Arginine (B) Tyrosine (C) Phenylalanine (D) Proline
Description : The limiting amino acid of rice is (A) Lysine (B) Tryptophan (C) Phenylalanine (D) Tyrosine
Description : Million-Nasse’s reaction is specific for the amino acid: (A) Tryptophan (B) Tyrosine (C) Phenylalanine (D) Arginine
Last Answer : Answer : B
Description : The following are true: a. thyroxine is formed by iodination of tyrosine b. the ratio of T3 :T4 secreted by the thyroid gland is 1:5 c. about 99.5% of thyroxines is protein bound d. T3 is more active than T4
Last Answer : T3 is more active than T4
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 which synthesizes many hormornes: (A) Valine (B) Phenylalanine (C) Alanine (D) Histidine
Description : All the following amino acids are optically active except (A) Tryptophane (B) Phenylalanine (C) Valine (D) Glycine
Description : Tyrosine hydroxylase is inhibited by (A) Catecholamines (B) α−Methyldopa (C) Phenylalanine (D) Vanillyl mandelic acid
Description : A characteristic of pheochromocytoma is elevated urinary excretion of (A) Dopamine (B) Tyrosine (C) Vinylmandelic acid (D) Phenylalanine
Description : Albinism is due to deficiency of the enzyme: (A) Phenylalanine hydroxylase (B) Tyrosinase (C) p-Hydroxyphenylpyruvic acid oxidase (D) Tyrosine dehydrogenase
Description : The amino acid which gives yellow colour with Ninhydrin in paper chromatography is (A) Tyrosine (B) Proline (C) Tryptophan (D) Alanine
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 : Melatonin is synthesised from (A) Phenylalanine (B) Tyrosine (C) Tryptophan (D) None of these
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 : Niacin can be synthesised in human beings from (A) Histidine (B) Phenylalanine (C) Tyrosine (D) Tryptophan
Description : Richner-Hanhart syndrome is due to defect in (A) Tyrosinase (B) Phenylalanine hydroxylase (C) Hepatic tyrosine transaminase (D) Fumarylacetoacetate hydrolase
Description : Serotonin is synthesised from (A) Serine (B) Phenylalanine (C) Tyrosine (D) Tryptophan
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 : Heme is synthesized from (A) Succinyl-CoA and glycine (B) Active acetate and glycine (C) Active succinate and alanine (D) Active acetate and alanine
Description : Branched chain amino acids are (A) Cysteine and cystine (B) Tyrosine and Tryptophan (C) Glycine and Serine (D) Valine, Leucine and Isoleucine
Description : An amino acid used for the synthesis of thyroid hormone is (A) Tyrosine (B) Tryptophan (C) Histidine (D) Proline
Description : Side chains of all following amino acids contain aromatic rings except (A) Phenyl alanine (B) Alanine (C) Tyrosine (D) Tryptophan
Description : Side chains of all amino acids contain aromatic rings except (A) Pheynl alanine (B) Alanine (C) Tyrosine (D) Tryptophan
Description : Along with CO2, NH3 and ATP, the amino acid that is needed in urea cycle is (A) Alanine (B) Isoleucine (C) Aspartate (D) Glycine
Description : 2-Amino 3-OH propanoic acid is (A) Glycine (B) Alanine (C) Valine (D) Serine
Description : The amino acid which is not optically active is (A) Alanine (B) Glycine (C) Glutamine (D) Lysine
Description : This amino acid cannot have optical isomers: (A) Alanine (B) Histidine (C) Threonine (D) Glycine
Description : The amino acid which detoxicated benzoic acid to form hippuric acid is (A) Glycine (B) Alanine (C) Serine (D) Glutamic acid
Description : Hormones thyroxine, adrenaline and the pigment melanin are formed from (a) tyrosine (b) proline (c) tryptophan (d) glycine.
Last Answer : (a) tyrosine
Description : In mammalian tissues serine can be a biosynthetic precursor of (A) Methionine (B) Glycine (C) Tryptophan (D) Phenylalanine
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