Description : In many proteins the hydrogen bonding produces a regular coiled arrangement which is called as (A) β-Helix (B) α-Helix (C) Both (A) and (B) (D) Spiral
Last Answer : Answer : B
Description : The α-Helix is held in a coiled conformation partially because of : (a) Optical activity (b) Hydrogen bonding (c) Resonance (d) Delocalization
Last Answer : Hydrogen bonding
Description : Both α-helix and β-pleated sheet conformation of proteins were proposed by (A) Watson and Crick (B) Pauling and Corey (C) Waugh and King (D) Y.S.Rao
Description : In proteins the α-helix and β-pleated sheet are examples of (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure
Description : Which of the following may characterize the “secondary structure” of proteins? (a) conformation of the protein backbone (b) α-Helix (c) parallel β-pleated sheet (d) all of the above
Last Answer : all of the above
Description : A coiled structure in which peptide bonds are folded in regular manner by (A) Globular proteins (B) Fibrous proteins (C) Both (A) and (B) (D) None of these
Last Answer : Answer : A
Description : The structural stability of the double helix of DNA is as cribbed largely to (A) Hydrogen bonding between adjacent purine bases (B) Hydrophobic bonding between staked purine and ... Hydrogen bonding between adjacent pyrimidine bases (E) Hydrogen bonding between purine and pyrimidine bases
Last Answer : Answer : D
Description : α-helix is stabilized by (A) Hydrogen bonds (B) Disulphide bonds (C) Salt bonds (D) Non-polar bonds
Description : α-Helix is formed by (A) Hydrogen bonds (B) Hydrophobic bonds (C) Electrostatic bonds (D) Disulphide bonds
Description : At the lowest energy level α-helix of polypeptide chain is stabilised (A) By hydrogen bonds formed between the H of peptide N and the carbonyl O of the residue (B) Disulphide bonds (C) Non polar bonds (D) Ester bonds
Description : What type of bonding helps in stabilishing the a-helix structure of proteins? -Chemistry
Last Answer : a-helix formation -» Intramolecular hydrogen bonding.
Description : What type of bonding helps in stabilising the -helix structure of proteins ?
Last Answer : Ans. In a -helix structure, polypeptide chain of amino acids coils as a right handed screw because of the formation of all possible Hydrogen bonds between — NH group at each amino residue and > C = 0 group of adjacent turn of helix.
Description : The nucleotide binding site of G-proteins is present on their (A) α-Subunit (B) β-Subunit α- and β- (C) γ-Subunit (D) δ-Subunit
Description : The a-helix of proteins is (A) A pleated structure (B) Made periodic by disulphide bridges (C) A non-periodic structure (D) Stabilised by hydrogen bonds between NH and CO groups of the main chain
Last Answer : Answer : C
Description : The helix angle in case of closely coiled helical spring is (A) less than 5° (B) 5° to 7° (C) 7° to 10° (D) more than 10°
Last Answer : (D) more than 10°
Description : The helix angle in case of closely coiled helical spring is (A) less than 10° (B) 10° to 15° (C) 15° to 20° (D) more than 20°
Last Answer : (A) less than 10°
Description : The helix angle is very small about 20. The spring is open coiled spring. a) Yes b) It is closed coiled spring c) That small angle isn’t possible d) None of the listed
Last Answer : b) It is closed coiled spring
Description : In double helix of DNA, the two DNA strands are (a) coiled around a common axis (b) coiled around each other (c) coiled differently (d) coiled over protein sheath.
Last Answer : (a) coiled around a common axis
Description : Angle of helix in a close coiled spring is (a) < 100 (b) >100 (c) =100 (d) None
Last Answer : (a) < 100
Description : Which of the following is the main structural feature of proteins? (a) Peptide linkage (b) Ester linkage (c) Ether linkage (d) α,β-Linkage
Last Answer : Peptide linkage
Description : The primary reason for preferring phentolamine as the α adrenergic blocker for performing diagnostic test for pheochromocytoma is: A. It produces rapid and short lasting α-adrenergic blockade B. It equally ... It is the most potent α blocker D. It has no additional β adrenergic blocking property
Last Answer : A. It produces rapid and short lasting α-adrenergic blockade
Description : In protein structure the α-helix and βpleated sheets are example of (A) Primary structure (B) Secondary structure (C) Tertiary structure (D) Quaternary structure
Description : α-helix is disrupted by certain amino acids like (A) Proline (B) Arginine (C) Histidine (D) Lysine
Description : The distance travelled per turn of α-helix in nm is (A) 0.34 (B) 0.44 (C) 0.54 (D) 0.64
Description : Each turn of α-helix contains the number of amino acids (A) 2.8 (B) 3.2 (C) 3.4 (D) 3.6
Description : An amino acid that does not take part in α helix formation is (A) Histidine (B) Tyrosine (C) Proline (D) Tryptophan
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 : Each turn of α-helix contains the amino acid residues (number): (A) 3.6 (B) 3.0 (C) 4.2 (D) 4.5
Description : Which of the following statements best describes the meaning of mutarotation ? (a) a rapid exchange between the α and β forms of diastereomeric sugars (b) a rapid exchange between the D ... between hydrogen and deuterated hydrogen (d) a slow change in optical rotation to reach an equilibrium value
Last Answer : a slow change in optical rotation to reach an equilibrium value
Description : Globular proteins have completely folded, coiled polypeptide chain and the axial ratio (ratio of length to breadth) is (A) Less than 10 and generally not greater than 3–4 (B) Generally 10 (C) Greater than 10 and generally 20 (D) Greater than 10
Description : All the following statements about TSH are true except (A) It is a glycoprotein (B) It is made up of α- and β-subunits (C) Receptor recognition involves both the subunits (D) Its subunit is identical with those of FSH and LH
Description : Foetal haemoglobin contains (A) Two α and two γ chains (B) Two β and two γ chains (C) Both (A) and (B) (D) None of these
Description : Cellulose is made up of the molecules of (A) α-glucose (B) β-glucose (C) Both of the above (D) None of these
Last Answer : A
Description : Proteins which interact with DNA and affect the rate of transcription possess the following structural motif: (A) Helix-turn-helix motif (B) Zinc finger motif (C) Leucine zipper motif (D) All of these
Description : Synthesis of RNA molecule is terminated by a signal which is recognised by (A) α-factor (B) β-factor (C) δ-factor (D) ρ
Description : Catabolism of thymidylate gives (A) α-alanine (B) β-alanine (C) α-aminoisobutyrate (D) β-aminoisobutyrate
Description : The mammalian DNA polymerase involved in error correction is (A) DNA polymerase α (B) DNA polymerase β (C) DNA polymerase γ (D) DNA polymerase δ
Description : Primase activity is present in (A) DNA polymerase II (B) DNA polymerase α (C) DNA polymerase β (D) DNA polymerase δ
Description : Replication of nuclear DNA in mammals is catalysed by (A) DNA polymerase α (B) DNA polymerase β (C) DNA polymerase γ (D) DNA polymerase III
Description : The key substance in the synthesis of purine, phosphoribosyl pyrophosphate is formed by (A) α-D-ribose 5-phosphate (B) 5-phospho β-D-ribosylamine (C) D-ribose (D) Deoxyribose
Description : The immediate parent of α, β and γ endorphins is (A) Pro-opiomelanocortin (B) β-lipotropin (C) ATCH (D) Lipoprotein
Description : Corticotropin releasing hormone controls the direct release of (A) Pro-opiomelanocortin (B) α MSH (C) β MSH (D) Endorphins
Description : Alloxan can experimentally induce diabetes mellitus due to (A) Stimulation of α cells of the islets of langerhans (B) Necrosis of the β cells of the islets (C) Potentiation of insulinase activity (D) Epinephrine like action
Description : Norepinephrine binds mainly to (A) α-Adrenergic receptors (B) β-Adrenergic receptrors (C) Muscarinic receptors (D) Nicotinic receptors
Description : Insulin receptor is made up of (A) One α-and one β-subunit (B) Two α-and two β-subunit (C) Two, α two β-and two γ-subunit (D) One α, one β-one γ-and one δ-subunit
Description : In the insulin receptor, tyrosine kinase domain is present in (A) α-Subunits (B) β-Subunits (C) γ-Subunits (D) δ-Subunits
Description : Insulin binding sites are present on the (A) α-subunits of insulin receptor (B) β-subunits of insulin receptor (C) γ-subunits of insulin receptor (D) α-and β−subunits of insulin receptor
Description : All of the following can be formed from pro-opiomelanocortin except (A) α-and β-MSH (B) β-and γ-Lipotropins (C) α-and β-Endorphins(D) FSH
Description : Tyrosine kinase activity is present in (A) α-Adrenergic receptors (B) β-Adrenergic receptors (C) Cholinergic receptors (D) Insulin receptors