Description : Thyroperoxidase iodinates (A) Free tyrosine in thyroid gland (B) Tyrosine residues of thyroglobulin (C) Tyrosine residues of thyroxine binding globulin (D) Tyrosine residues of thyroxine binding prealbumin
Last Answer : Answer : B
Description : The tyrosine residues per molecule of thyroglobulin is (A) 85 (B) 95 (C) 115 (D) 135
Last Answer : Answer : C
Description : Edman’s reaction can be used to (A) Determine the number of tyrosine residues in a protein (B) Determine the number of aromatic amino acid residues in a protein (C) Determine the amino acid sequence of a protein (D) Hydrolyse the peptide bonds in a protein
Description : Which one of the following hormones is derived most completely from tyrosine? (A) Glucagon (B) Thyroxine (C) Insulin (D) Prostaglandins
Description : Thyroxine is derived from (A) Tyrosine (B) Tyranine (C) Taurine (D) Tryptaine
Last Answer : Answer : A
Description : T3 is (A) Thyroxine (B) Triodo thyronine (C) Triodo tyrosine (D) Reverse tri iodo thyronine
Description : Tyrosine is required for the synthesis of all of the following except (A) Melatonin (B) Epinephrine (C) Norepinephrine (D) Thyroxine 222 MCQs IN BIOCHEMISTRY
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 : Hormones thyroxine, adrenaline and the pigment melanin are formed from (a) tyrosine (b) proline (c) tryptophan (d) glycine.
Last Answer : (a) tyrosine
Description : Each turn of α-helix contains the amino acid residues (number): (A) 3.6 (B) 3.0 (C) 4.2 (D) 4.5
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 : Buffering action of haemoglobin is mainly due to its (A) Glutamine residues (B) Arginine residues (C) Histidine residues (D) Lysine residues
Description : Blue print for genetic information residues in (A) mRNA (B) tRNA (C) rRNA (D) DNA
Last Answer : Answer : D
Description : Glycoproteins are marked for destruction by removal of their (A) Oligosaccharide prosthetic group (B) Sialic acid residues (C) Mannose residues (D) N-terminal amino acids
Description : Zinc finger motif is formed in some proteins by binding of zinc to (A) Two cysteine residues (B) Two histidine residues (C) Two arginine residues (D) Two cysteine and two histidine residues or two pairs of two cysteine residues each
Description : Leucine zipper motif is seen in some helical proteins when leucine residues appear at every (A) 3rd position (B) 5th position (C) 7th position (D) 9th position
Description : Number of guanine and cytosine residues is equal in (A) mRNA (B) tRNA (C) DNA (D) None of these
Description : Ultraviolet light can damage a DNA strand causing (A) Two adjacent purine residue to form a covalently bounded dimer (B) Two adjacent pyrimidine residues to form covalently bonded dimer (C) Disruption of phosphodiesterase linkage (D) Disruption of non-covalent linkage
Description : Number of amino acid residues in glucagons is (A) 29 (B) 34 (C) 51 (D) 84
Description : Amino acid residues which are essential for the biological activity of PTH are (A) N-terminal 34 amino acids (B) N-terminal 50 amino acids (C) C-terminal 34 amino acids (D) C-terminal 50 amino acids
Description : The number of amino acid residues in PTH: (A) 51 (B) 84 (C) 90 (D) 115
Description : Number of amino acid residues in prolactin is (A) 51 (B) 84 (C) 191 (D) 198
Description : Number of amino acid residues in human growth hormone is (A) 51 (B) 84 (C) 191 (D) 198
Description : Glycosphingolipids are a combination of (A) Ceramide with one or more sugar residues (B) Glycerol with galactose (C) Sphingosine with galactose (D) Sphingosine with phosphoric acid
Description : Bonds that are formed between two cysteine residues is (A) Disulphide (B) Peptide (C) Electrostatic (D) Hydrophobic
Description : Collagen and elastin have the following similarity: (A) Both are triple helices (B) Both have hydroxyproline residues (C) Both have hydrolysine residues (D) Both are glycoproteins
Description : Pre-proinsulin contains a signal sequence having (A) 9 amino acid residues (B) 19 amino acid residues (C) 27 amino acid residues (D) 33 amino acid residues
Description : The number of amino acid residues in preproinsulin is (A) 51 (B) 84 (C) 109 (D) 119
Description : Insulin is made up of (A) A single polypeptide chain having 51 amino acid residues (B) A single polypeptide chain having 84 amino acid residues (C) A-chain having 21 and B-chain having 30 amino acid residues (D) A-chain having 30 and B-chain having 21 amino acid residues
Description : The number of amino acid residues in calcitonin in (A) 9 (B) 32 (C) 51 (D) 84
Description : All of the following are required for hydroxylation of proline residues except (A) Ascorbic acid (B) Glutamate (C) Ferrous ions (D) Molecular oxygen
Description : All the following statement about hydroxyproline are true except (A) There is no codon for hydroxyproline (B) It is present in large amounts in collagen (C) Free proline cannot be hydroxylated to hydroxyproline (D) Hydroxylation of proline residues is catalysed by a dioxygenase
Description : A disulphide bond can be formed between (A) Two methionine residues (B) Two cysteine residues (C) A methionine and a cysteine residue (D) All of these
Description : Chymotrypsin is specific for peptide bonds containing (A) Uncharged amino acid residues (B) Acidic amino acids (C) Basic amino acid (D) Small amino acid residues
Description : The enzyme trypsin is specific for peptide bonds of (A) Basic amino acids (B) Acidic amino acids (C) Aromatic amino acids (D) Next to small amino acid residues
Description : In glycoproteins, carbohydrate residues are attached to which group of the polypeptide chain?
Last Answer : Hydroxyl group of serine or threonine.
Description : Normal range of total thyroxine in serum is (A) 0.8–2.4 ng/dl (B) 0.8–2.4 µg/dl (C) 5–12 ng/dl (D) 5–12 µg/dl
Description : The normal serum level of thyroxine (T4) is (A) 2.0–4.0 µg/100 ml (B) 5.5–13.5 µg/100 ml (C) 14.0–20.3 µg/100 ml (D) 20.0–25.0 µg/100 ml
Description : __________ hormone is a single chain polypeptide having 32 amino acids with molecular weight of 3,600. (A) Testosteron (B) Thyroxine (C) Calcitonine (D) Vasopressin
Description : Which of the following statements is correct? (A) Thyroxine inhibits utilization of glucose (B) Insulin increases utilization of glucose (C) Glucagon promotes muscle glycogenolysis (D) Insulin inhibits lipogenesis from carbohydrates
Description : Calcitomica is antagonist to (A) Serotonin (B) Thyroxine (C) Tri iodo thyronine (D) Para thyroid hormone
Description : Protein bound iodine is _________ bound to protein. (A) Iodine (B) Thyroid hormones (C) Thyroxine (D) Tri iodo thyronine
Description : Binding of thyroxine to its receptors (A) Activates Adenylate cyclase (B) Activates guanylate cyclase (C) Activates a stimulatory G-protein (D) Increases transcription
Description : When thyroxine binding globulin and thyroxine binding pre-albumin are saturated with thyroxine, the excess hormone is transported by (A) Albumin (B) Gamma globulins (C) Transcortin (D) None of these
Description : Thyroid hormones are present in blood (A) In free form (B) In association with thyroxine binding globulin (TBG) (C) In association with thyroxine binding prealbumin (TBPA) (D) Mainly in association with TBG, partly in free form and sometimes in association with TBPA also
Description : An enzyme required for the synthesis of thyroid hormones is (A) Iodinase (B) Deiodinase (C) Thyroperoxidase (D) Thyroxine synthetase
Description : TSH stimulates the synthesis delete (A) Thyroxine (B) Adrenocorticoids (C) Epinephrine (D) Insulin
Description : ACTH stimulates the secretion of (A) Glucocorticoids (B) Epinephrine (C) Thyroxine (D) Luteinizing hormone
Description : Acromegaly results due to excessive release of (A) Thyroxine (B) Growth hormone (C) Insulin (D) Glucagon
Description : Hormone that binds to intracellular receptor is (A) Adrenocorticotropic hormone (B) Thyroxine (C) Follicle stimulating hormone (D) Glucagon