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
Last Answer : Answer : A
Description : Claisen condensation gives__________ a) Hydroxyl compound b) β- keto ester c) Γ- diketone d) Α-diketone
Last Answer : b) β- keto ester
Description : Instead of ester link plasmalogens possess an other link in position: (A) α (B) β (C) γ (D) None of these FATS AND FATTY ACID METABOLISM 93
Last Answer : Answer : B
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 : Which one of the following organic compounds has fruity smell? (1) Alcohol (2) Aldehyde (3) Ester (4) Ether
Last Answer : (3) Ester Explanation: Esters are common in organic chemistry and biological materials, and often have a characteristic pleasant, fruity odour. This leads to their extensive use in the fragrance and ... ester as the reaction product. Esters are widespread in nature and are widely used in industry.
Description : An alcohol is related to an ester as a hydroxide compound is related to: w) an acid x) a ketone y) an ether z) a salt
Last Answer : ANSWER: Z -- A SALT
Last Answer : Ester
Description : The carbon of the pentose in ester linkage with the phosphate in a nucleotide structure is (A) C1 (B) C3 (C) C4 (D) C5
Last Answer : Answer : D
Description : The cell membrane of archaeal cells contains a. A monolayer. b. Sterols. c. Ester linkage d. All of the above (A—C are correct.)
Last Answer : a. A monolayer.
Description : The local anaesthetics having amide linkage differ from those having ester linkage in that the amidelinked local anaesthetics: A. Are not surface anaesthetics B. Have a shorter duration of action C. Are degraded in the plasma D. Do not show cross-sensitivity with esterlinked local anaesthetic
Last Answer : D. Do not show cross-sensitivity with esterlinked local anaesth
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 : 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
Description : In many proteins the hydrogen bonding produces a regular coiled arrangement called (A) α-helix (B) β-helix (C) Both (A) and (B) (D) None of these
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 : Ephedrine is similar to adrenaline in the following feature: A. Potency B. Inability to penetrate blood-brain barrier C. Duration of action D. Producing both α and β adrenergic effects
Last Answer : D. Producing both α and β adrenergic effects
Description : Which bond is present in the primary structure of protein? (A) Ester (B) Hydrogen (C) Ionic bond (D) Peptide
Description : What is peptide linkage?
Last Answer : What is the answer ?
Description : Biuret test is specific for (A) Two peptide linkage (B) Phenolic group (C) Imidazole ring (D) None of these
Description : Base-catalyzed condensation of two ester molecules to form an alcohol and β-keto ester is called (a) Claisen condensation (b) Corey-House reaction (c) Aldol condensation (d) Transesterification
Last Answer : Claisen condensation
Description : Which of the following statements best describes the difference between amylose and amylopectin? (a) Amylose is a branched polysaccharide while amylopectin is a chain polysaccharide. (b) Amylose is a ... of thousands of D-glucose units while amylopectin is composed of thousands of D-galactose units.
Last Answer : Amylose is a straight-chain polysaccharide while amylopectin is a branched polysaccharide
Description : Ethanol (CH3CH2OH) and dimethyl ether (CH3OCH3) are best considered : (a) structural isomers (b) stereoisomers (c) enantiomers (d) diastereomers
Last Answer : structural isomers
Description : Wolman’s disease is due to deficiency of (A) Cholesteryl ester hydrolase (B) Hexosaminidase A (C) α-Fucosidase (D) Arylsulphatase A
Description : In biotin-containing enzymes, the biotin is bound to the enzyme by (A) An amide linkage to carboxyl group of glutamine (B) A covalent bond with CO2 (C) An amide linkage to an amino group of lysine (D) An amide linkage to α-carboxyl group of protein
Last Answer : Answer : C
Description : Ninhydrin with evolution of CO2 forms a blue complex with (A) Peptide bond (B) α-Amino acids (C) Serotonin (D) Histamine
Description : Digestion of proteins involves (a) changes in secondary structure only (b) cleavage of peptide linkages (c) removal of all carboxyl groups in the form of CO2. (d) removal of all NH2 groups in the form of NH3
Last Answer : cleavage of peptide linkages
Description : Which of the following is the quaternary structure of proteins concerned with? (a) sequence of amino acids in the peptide chain (b) description of the way the peptide chains are arranged with ... (c) location of the disulfide bridges in the peptide chain (d) conformation of the protein backbone
Last Answer : description of the way the peptide chains are arranged with respect to each other
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 : Radiations which is not emitted during radioactivity is – (1) α rays (2) β rays (3) γ rays (4) Cathode rays
Last Answer : (4) Cathode rays Explanation: Radioactivity is the process by which a nucleus of an unstable atom loses energy by emitting particles of ionizing radiation. It includes the emission of energetic alpha particles (α), beta particles (β), and gamma rays.
Description : Radioactive elements emit – (1) Radiowaves (2) Infrared waves (3) Ultraviolet waves (4) α, β and γ radiations
Last Answer : (4) α, β and γ radiations Explanation: The phenomenon of spontaneous emission of certain kinds of radiations by some elements is called radioactivity and the elements emitting such radiations are called ... the radioactive substances are separated in to three types, called a, b and g rays.
Description : When cathode rays strike a target of high atomic weight, they give rise to – 1) α -rays (2) β and γ rays (3) X-rays (4) positive rays
Last Answer : (3) X-rays Explanation: When cathode rays strike a solid target of high atomic weight and high melting point such as tungsten, molybdenum, etc, they give rise to a highly pen-etrating radiation called the X-rays (LIT Physics by Dr. P.K Aganval).
Description : The mutarotation of glucose is characterized by : (a) a change from an aldehyde to ketone structure. (b) a change of specific rotation from a (+) to a (–) value. (c) the presence of an intramolecular bridge structure. (d) the irreversible change from α-D to the β-D form.
Last Answer : the presence of an intramolecular bridge structure.
Description : α-D-Glucose is different from β-D-glucose (a) in the configuration at C-1 (b) because they are mirror images of each other (c) because they are enantiomers (d) because they are geometrical isomers
Last Answer : in the configuration at C-1
Description : Which of the following would give a positive Tollen’s test? (a) α-D-glucopyranose (b) methyl β-D-glucopyranoside (c) sucrose (d) methyl α-D-ribofuranoside
Last Answer : α-D-glucopyranose
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 : Carboxylic acid reacts with halogen in presence of red P to gives__________ a) α-halogen acids b) β-halogen acid c) Acid halide d) Dicarboxylic acid
Last Answer : a) α-halogen acids
Description : Which of the following is the least likely to be involved in stabilising the three-dimensional folding of most proteins (a) Hydrogen bonds (b) Electrostatic interaction (c) Hydrophobic interaction (d) Ester bonds
Last Answer : (d) Ester bonds
Description : Pick up the correct definition from the following with response to GIS. (A) Common boundary between two areas of a locality is known as adjacency (B) The area features which are wholly ... property which describes the linkage between line features is defined as connectivity (D) All of these
Last Answer : Answer: Option D
Description : What is the peptide bond that connects amino acids in proteins? -Biology
Last Answer : answer:
Description : In denaturation of proteins, the bond which is not broken: (A) Disulphide bond (B) Peptide bond (C) Hydrogen bond (D) Ionic bond
Description : The bond in proteins that is not broken under usual conditions of denaturation: (A) Hydrophobic bond (B) Hydrogen bond (C) Disulphide bond (D) Peptide bonds
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
Description : Proteins react with biuret reagent which is suggestive of 2 or more (A) Hydrogen bonds (B) Peptide bonds (C) Disulphide bonds (D) Hydrophobic bonds
Description : The bond in proteins that is not hydrolysed under usual conditions of denaturation: (A) Hydrophobic bond (B) Hydrogen bond (C) Disulphide bond (D) Peptide bonds
Description : All the following statements about pepsin are correct except (A) It is smaller than pepsinogen (B) It is formed by the action of HCl on its precursor (C) Its optimum pH is 1.0–2.0 (D) It hydrolyses the C-terminal and N-terminal peptide bonds of proteins
Description : Denaturation of proteins results in (A) Disruption of primary structure (B) Breakdown of peptide bonds (C) Destruction of hydrogen bonds (D) Irreversible changes in the molecule
Description : Proteins that are secreted by cells are generally a. not synthesized on membrane-bound ribosomes b. initially synthesized with a signal peptide or leader sequence at their C terminal c. found in ... endocytosis e. secreted in a form that is larger than the form present in the endoplasmic reticulum
Last Answer : found in vesicles and secretory granules
Description : Which statement is NOT true about non-steroid (peptide) hormones? A) They are derived from peptides, proteins, polypeptides, and derivatives of amino acids. B) They bind to receptors on the cell surface. ... They create an enzyme cascade effect. E) They enter the cell in order to have an effect.
Last Answer : E) They enter the cell in order to have an effect.
Description : Peptide bonds are found in: a) carbohydrates b) lipids c) nucleic acids d) proteins
Last Answer : ANSWER: D -- PROTEINS