Description : Which one of the following is an essential amino acid? (A) Arginine (B) Tyrosine (C) Phenylalanine (D) Proline
Last Answer : Answer : C
Description : Thyroid hormones are synthesized by the iodination of the amino acid: (A) Glycine (B) Phenylalanine (C) Alanine (D) Tyrosine
Last Answer : Answer : D
Description : Hormones thyroxine, adrenaline and the pigment melanin are formed from (a) tyrosine (b) proline (c) tryptophan (d) glycine.
Last Answer : (a) tyrosine
Description : Millon’s test is for identification of (A) Tyrosine (B) Tryptophan (C) Proline (D) Arginine
Last Answer : Answer : A
Description : In the B chain of insulin molecule, the Nterminal amino acid is (A) Proline (B) Threonine (C) Phenylalanine (D) Lysine
Description : In A chain of the insulin molecule the Nterminal amino acid is (A) Glycine (B) Valine (C) Serine (D) Phenylalanine
Description : An amino acid required for porphyrin synthesis is (A) Proline (B) Glycine (C) Serine (D) Histidine
Description : Carnitine is synthesized from (A) Lysine and methionine (B) Glycine and arginine (C) Aspartate and glutamate (D) Proline and hydroxyproline
Description : All the following amino acids are optically active except (A) Tryptophane (B) Phenylalanine (C) Valine (D) Glycine
Description : Optical isomers of all aminoacids exist except (A) Glycine (B) Arginine (C) Alanine (D) Hydroxy proline
Description : The basic amino acid: (A) Glycine (B) Leucine (C) Histidine (D) Proline
Description : In mammalian tissues serine can be a biosynthetic precursor of (A) Methionine (B) Glycine (C) Tryptophan (D) Phenylalanine
Last Answer : Answer : B
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 : An amino acid used for the synthesis of thyroid hormone is (A) Tyrosine (B) Tryptophan (C) Histidine (D) Proline
Description : Melatonin is synthesised from (A) Phenylalanine (B) Tyrosine (C) Tryptophan (D) None of these
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 : In the synthesis of Angiotensin I, rennin acts on Angiotensinogen and cleaves the (A) Leucine – leucine at 10 and 11 position (B) Valine – tyrosine at 3 and 4 position (C) Isoleucine – histidine at 5 and 6 position (D) Proline – histidine at 7 and 8 position
Description : The deficiency of copper decreases the activity of the enzyme: (A) Lysine oxidase (B) Lysine hydroxylase (C) Tyrosine oxidase (D) Proline 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 : 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 : 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 : An amino acid that does not form an αhelix is (A) Asparagine (B) Tyrosine (C) Tryptophan (D) Proline
Description : An essential amino acid in man is (A) Proline (B) Threonine (C) Asparagine (D) Tyrosine
Description : The amino acid which gives yellow colour with Ninhydrin in paper chromatography is (A) Tyrosine (B) Proline (C) Tryptophan (D) Alanine
Description : Serotonin is synthesised from (A) Serine (B) Phenylalanine (C) Tyrosine (D) Tryptophan
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 : An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan
Description : The limiting amino acid of rice is (A) Lysine (B) Tryptophan (C) Phenylalanine (D) Tyrosine
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 : Million-Nasse’s reaction is specific for the amino acid: (A) Tryptophan (B) Tyrosine (C) Phenylalanine (D) Arginine
Description : Sakaguchi’s reaction is specific for (A) Tyrosine (B) Proline (C) Arginine (D) Cysteine
Description : An amino acid that does not form an αhelix is (A) Valine (B) Proline (C) Tyrosine (D) Tryptophan
Description : Phenylalanine is the precursor of (A) L-DOPA (B) Histamine (C) Tyrosine (D) Throxine
Last Answer : C
Description : Which among the following is a nutritionally essential amino acid for man? (A) Alanine (B) Glycine (C) Tyrosine (D) Isoleucine
Description : Branched chain amino acids are (A) Cysteine and cystine (B) Tyrosine and Tryptophan (C) Glycine and Serine (D) Valine, Leucine and 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
Description : The α-carbon of all the amino acids is a chirality center except for __________. (a) Glycine (b) Threonine (c) Proline (d) Aspartic acid
Last Answer : Glycine
Description : Which of the following amino acids has a heterocyclic R group? (a) Glycine (b) Threonine (c) Proline (d) Aspartic acid
Last Answer : Proline
Description : Which of the following amino acid is related to drought tolerance in plants ? a. Glycine b. Proline c. Glutamic acid d. None of these
Last Answer : b. Proline
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
Last Answer : (D) Tryptophan
Description : All α-amino acids give positive (A) Million’s test (B) Biurete test (C) Xanthproteic test (D) Ninhydrine test
Description : Which of the following is the simplest amino acid? (a) Alanine (b) Asparagine (c) Glycine (d) Tyrosine
Last Answer : (c) Glycine
Description : Pyridoxine deficiency can be diagnosed by measuring the urinary excretion of xanthurenic acid following a test dose of (A) Glycine (B) Histidine (C) Tryptophan (D) Pyridoxine