Description : An amino acid used for the synthesis of thyroid hormone is (A) Tyrosine (B) Tryptophan (C) Histidine (D) Proline
Last Answer : Answer : A
Description : An amino acid that does not form an αhelix is (A) Asparagine (B) Tyrosine (C) Tryptophan (D) Proline
Last Answer : Answer : D
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
Last Answer : Answer : B
Description : An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan
Last Answer : Answer : C
Description : An amino acid that does not form an αhelix is (A) Valine (B) Proline (C) Tyrosine (D) Tryptophan
Description : Million’s test is positive for (A) Phenylalanine (B) Glycine (C) Tyrosine (D) Proline
Description : Tryptophan could be considered as precursor of (A) Melanotonin (B) Thyroid hormones (C) Melanin (D) Epinephrine
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 : 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 : Which one of the following hormones contains iodine? (1) Thyroxine (2) Testosterone (3) Insulin (4) Adrenaline
Last Answer : (1) Thyroxine Explanation: Thyroxine is produced by attaching iodine atoms to the ring structures of this protein's tyrosine residues; thyroxine (T4) contains four iodine atoms
Last Answer : (1) Thyroxine Explanation: Thyroxine is produced by attaching iodine atoms to the ring structures of this protein's tyrosine residues; thyroxine (T4) contains four iodine atoms, while triiodothyronine (T3), otherwise identical to T4, has one less iodine atom per molecule.
Description : Which one of the following hormones is derived most completely from tyrosine? (A) Glucagon (B) Thyroxine (C) Insulin (D) Prostaglandins
Description : Thyroid hormones are synthesized by the iodination of the amino acid: (A) Glycine (B) Phenylalanine (C) Alanine (D) Tyrosine
Description : Homogentisic acid is formed from (A) Homoserine (B) Homocysteine (C) Tyrosine (D) Tryptophan
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 : The following are true about the neurotransmitters: a. acetylcholine is inactivated mainly by presynaptic reuptake b. tyrosine is essential for the formation of dopamine c. noradrenaline is inactivated mainly by hydrolysis d. adrenaline is formed from methylation of the noradrenaline
Last Answer : adrenaline is formed from methylation of the noradrenaline
Description : The colour of human skin is produced by (1) Haemoglobin(2) Insulin (3) Adrenaline (4) Melanin
Last Answer : Melanin
Description : Formation of melanin from tyrosine requires the action of (A) Dopa decarboxylation (B) Diamine oxidase (C) Peroxidase (D) Tyrosinase
Description : Which among the following has an imidazole group? (A) Histidine (B) Tryptophan (C) Proline (D) Hydroxy proline
Description : Which one of the following is sulphur-containing amino acid? (A)Tryptophan (B) Cystine (C) Proline (D) Lysine
Last Answer : (B) Cystine
Description : Melanin pigment protects from which of the following radiations ?
Last Answer : Melanin pigment protects from which of the following radiations ? A. X-rays B. Infra-red rays C. Visible rays D. UV rays
Description : Retina contains this photosensitive pigment: (A) Rhodopsin (B) Opsin (C) Retinol (D) Melanin
Description : The brown-black pigment of the skin that is transferred to other epidermal cells and gives the skin its color is called A. albumin B. collagen C. keratin D. melanin
Last Answer : Ans: D
Description : The pigment which gives colour to the human skin is – (1) Melanin (2) Rhodopsin (3) Iodopsin (4) Anthocyanin
Last Answer : (1) Melanin Explanation: Human skin color is primarily due to the presence of melanin in the skin. Skin color ranges from almost black to white with a pinkish tinge due to blood vessels underneath. In animals melanin pigments are derivatives of the amino acid tyrosine.
Description : True statements about chloroquine include: a. is safer than hydroxychloroquine at equivalent dose b. can cause corneal deposition c. causes posterior subcapsular cataract d. chloroquine is bound to the melanin of the retinal pigment epithelium e. causes reversible toxic maculopathy
Last Answer : can cause corneal deposition
Description : The pigment which gives colour to the human skin is (1) Melanin (2) Rhodopsin (3) Iodopsin (4) Anthocyanin
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 : 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 : 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 : 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 : An essential amino acid in man is (A) Proline (B) Threonine (C) Asparagine (D) Tyrosine
Description : Which one of the following is an essential amino acid? (A) Arginine (B) Tyrosine (C) Phenylalanine (D) Proline
Description : Sakaguchi’s reaction is specific for (A) Tyrosine (B) Proline (C) Arginine (D) Cysteine
Description : The amino acid tryptophan is the precursor for the synthesis of (a) estrogen and progesterone (b) cortisol and cortisone (c) melatonin and serotonin (d) thyroxine and triiodothyronine
Last Answer : (c) melatonin and serotonin
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
Description : All amino acids are optically active except (A) Glycine (B) Serine (C) Threonine (D) Tryptophan
Description : The amino acid which contains an indole group is (A) Histidine (B) Arginine (C) Glycine (D) Tryptophan
Description : The primary structure of fibroin, the principal protein of silk worm fibres consists almost entirely of (A) Glycine (B) Aspartate (C) Keratin (D) Tryptophan
Description : In mammalian tissues serine can be a biosynthetic precursor of (A) Methionine (B) Glycine (C) Tryptophan (D) Phenylalanine
Description : Adrenalin is synthesized from (A) Adenine (B) Adenosine (C) Tyrosine (D) Tryptophan 230 MCQs IN BIOCHEMISTRY
Description : Melatonin is synthesised from (A) Phenylalanine (B) Tyrosine (C) Tryptophan (D) None of these
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 : Niacin can be synthesised in human beings from (A) Histidine (B) Phenylalanine (C) Tyrosine (D) Tryptophan