Description : Hormonal activity of ACTH is completely lost on removal of (A) 5 C-terminal amino acids (B) 10 C-terminal amino acids (C) 15 C-terminal amino acids (D) None of these
Last Answer : Answer : D
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
Last Answer : Answer : A
Description : Biological activity of gastrin is present in the (A) Four N-terminal amino acids (B) Four C-terminal amino acids (C) Five N-terminal amino acids (D) Five C-terminal amino acids
Last Answer : Answer : B
Description : Adrenocorticotropic hormone (ACTH) is a single polypeptide containing (A) 25 amino acid (B) 39 amino acid (C) 49 amino acid (D) 52 amino acid 208 MCQs IN BIOCHEMISTRY
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 : The amino terminal of all polypeptide chain at the time of synthesis in E. coli is tagged to the amino acid residue: (A) Methionine (B) Serine (C) N-formyl methinine(D) N-formal serine
Last Answer : Answer : C
Description : Bence-Jones proteins possess all the following properties except (A) They are dimers of light chains (B) Their amino acids sequences are identical (C) Their N-terminal halves have variable amino acid sequences (D) Their C-terminal halves have constant amino acid sequences
Description : The sequence of amino acid in which the biological value of parathormone is (A) 1–15 (B) 1–34 (C) 30–50 (D) 50–84
Description : ACTH is a polypeptide made up of (A) 39 amino acids (B) 41 amino acids (C) 51 amino acids (D) 84 amino acids
Description : All the following statements about proopiomelanocortin are true except (A) It is made up of 285 amino acids (B) It is synthesised in pars intermedia and anterior lobe of pituitary gland ... ) It is the precursor of corticotropin like intermediate lobe peptide and endorphins 218 MCQs IN BIOCHEMISTRY
Description : N-terminal amino acids of a polypeptide are estimated by (A) Edmann reaction (B) Sanger’s reagent (C) Formaldehyde test (D) Ninhydrine reaction
Description : The hormone activating the glycogen synthase activity is (A) Insulin (B) Glucagon (C) Epinephrine (D) ACTH
Description : The figure shows a hypothetical tetrapeptide portion of a protein with parts labelled A-D. Which one of the following options is correct? - HN - CH - CO - NH - CH - CO - NH - CH - CO - ... -terminal amino acid and D is N-terminal amino acid. (d) A is a sulphur containing amino acid methionine.
Last Answer : (a) D is the acidic amino acid-glutamic acid.
Description : In the B chain of insulin molecule, the C-terminal amino acid: (A) Threonine (B) Tyrosine (C) Glutamate (D) Valine
Description : An important reaction for the synthesis of amino acid from carbohydrate intermediates is transamination which requires the cofactor: (A) Thiamin (B) Riboflavin (C) Niacin (D) Pyridoxal phosphat
Description : Which of the following is the first step in the determination of the primary structure of proteins? (a) determining the number and kind of amino acids in the peptide (b) reducing the disulfide bridges ... (c) protecting the N-terminal of the peptide (d) protecting the C-terminal of the peptide
Last Answer : reducing the disulfide bridges in the protein
Description : A middle aged female presented with following symptoms - Hirsutism, fragility of skin, with easy bruising, broad purplish striae and signs of proximal myopathy. The first step in ... Exclude exogenous Glucocorticoid use 3) Advice plasma ACTH estimation 4) Advice dexamethasone overnight test
Last Answer : Correct Answer: 2) Exclude exogenous Glucocorticoid use
Description : The shape of an enzyme and consequently its activity can be reversibly altered from moment to moment by (A) Heat (B) Amino acid substrate (C) Allosteric subunits (D) Sulfur substitutions
Description : Different isoenzymes of an enzyme have the same (A) Amino acid sequence (B) Michaelis constant (C) Catalytic activity (D) All of these
Description : The isoenzymes of LDH (A) Differ only in a single amino acid (B) Differ in catalytic activity (C) Exist in 5 forms depending on M and H monomer contents (D) Occur as monomers
Description : The activity of mammalian L-amino acid oxidase, an FMN – flavo protein, is quite (A) Slow (B) Rapid (C) Both (A) and (B) (D) None of these
Description : Along the α-helix each amino acid residue advances in nm by (A) 0.15 (B) 0.10 (C) 0.12 (D) 0.20
Description : Thyroid stimulating hormone is a dimer. The α-subunits of TSH, LH, FSH are identical. Thus the biological specificity must therefore be β subunit in which the number of amino acids is (A) 78 (B) 112 (C) 130 (D) 199
Description : Haemoglobin is a/an (A) Amino acid (B) Biological catalyst (C) Protein (D) Enzyme
Last Answer : (C) Protein
Description : The newly entering amino acyl tRNA into A site requires (A) EF-II (B) Ribosomal RNA (C) mRNA (D) EF-I
Description : In the process of elongation of chain binding of amino acyl tRNA to the A site requires (A) A proper codon recognition (B) GTP (C) EF-II (D) GDP
Description : Biological activity of tocopherols has been attributed in part to their action as (A) Antioxidant (B) Anticoagulents (C) Provitamin (D) Carriers in electron transport system
Description : One international unit (I.U) of vitamin D is defined as the biological activity of (A) 0.025 µg of cholecalciferol (B) 0.025 µg of 7-dehydrocholecalciferol (C) 0.025 µg of ergosterol (D) 0.025 µg of ergocalciferol VITAMINS 113
Description : In E. coli the chain initiating amino acid in protein synthesis is (A) N-formyl methionine(B) Methionine (C) Serine (D) Cysteine
Description : The half-life of a protein depends upon its (A) Signal sequence (B) N-terminus amino acid (C) C-terminus amino acid (D) Prosthetic group
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 : The first amino acid incorporated in a polypeptide in a ribosome of a bacterium is (A) N formyl methionine (B) Methionine (C) Alamine (D) Glycine
Description : The first amino acid incorporated in a polypeptide in a ribosome of a human is (A) N formyl methionine (B) Methionine (C) Phenyl alanine (D) Hydroxy lysine
Description : In urea synthesis, the amino acid functioning solely as an enzyme activator: (A) N-acetyl glutamate(B) Ornithine (C) Citrulline (D) Arginine
Description : Body water is regulated by the hormone: (A) Oxytocin (B) ACTH (C) FSH (D) Epinephrine
Description : Which of the following hormones is not involved in carbohydrate metabolism? (A) ACTH (B) Glucagon (C) Vasopressin (D) Growth hormone
Description : Gastric Secretion is regulated by the hormone: (A) Glucagon (B) Gastrin (C) Epinephrin (D) ACTH
Description : Proopiomelanocortin is the precussor of (A) ACTH (B) β-tropin (C) Endorphins (D) All of these
Description : Which of the following hormone is not under the control of ACTH? (A) Aldosterone (B) Cortisol (C) Corticosterone (D) Deoxycorticosterone
Description : Which one of the following is not liberated by the adenohypophysis? (A) Growth hormone (B) TSH (C) ACTH (D) Gonadotropin
Description : Secretion of androgens is increased by (A) LH (B) FSH (C) ACTH (D) Growth hormone
Description : Secretion of mineralcorticoids is increased by (A) ACTH (B) Angiotensin (C) Hypokalaemia (D) Hypernatraemia
Description : Acromegaly results from overproduction of (A) ACTH during childhood (B) TSH during adult life (C) Growth hormone during childhood (D) Growth hormone during adult life HORMONE METABOLISM 219
Description : Regulation of ACTH secretion occurs through (A) Corticotropin releasing hormone (CRH) and corticotropin release inhibiting hormone (CRIH) of hypothalamus (B) Feedback inhibition by cortisol (C) CRH and feedback inhibition by cortisol (D) CRIH and feedback inhibition by cortisol
Description : All the following statements about ACTH are true except (A) It is a tropic hormone (B) Its target cells are located in adrenal cortex (C) Its receptors are located in the cell membrane (D) Its second messenger is inositol triphosphate
Description : Precursor of ACTH is (A) Cholesterol (B) Pregnenolone (C) Corticotropin (D) Pro-opiomelanocortin
Description : A nonapeptide among the following is (A) Antidiuretic hormone (B) Insulin (C) ACTH (D) Thyrotropin releasing hormone
Description : Secretion of MSH is regulated by (A) Feedback mechanism (B) Melatonin (C) Hypothalamic hormones (D) ACTH HORMONE METABOLISM 217
Description : Cyclic AMP acts as the second messenger for all of the following except (A) Oxytocin (B) TSH (C) ACTH (D) FSH 216 MCQs IN BIOCHEMISTRY
Description : The production of progesterone by corpus luteum cell is stimulated by (A) LH (B) TSH (C) ACTH (D) MSH