Chapter 31

The cell membranes are mainly composed of (a) fats (b) proteins (c) phospholipids (d) carbohydrates

Which one of the following is a non-reducing sugar? (a) glucose (b) sucrose (c) fructose (d) arabinose

Which of the following is a polysaccharide? (a) Gentiobiose (b) fructose (c) dextrin (d) all of these

Which of the following reagents cannot distinguish between glucose and fructose? (a) Tollen's reagent (b) Fehling's solution (c) Benedict's solution (d) All of these

Reducing property of monosaccharides is due to the presence of (a) keto group (b) acetal group (c) anomeric hydroxyl group (d) - CHO group

Glucose gives silver mirror test with Tollen's reagent. It shows the presence of (a) ketonic group (b) aldehydic group (c) alcoholic group (d) acidic group

Which of the following is an amphoteric acid? (a) glycine (b) salicylic acid (c) benzoic acid (d) citric acid

The aldehyde which is formed during photosynthesis of plants is (a) propanal (b) methanal (c) acetaldehyde (d) phenylmethanal

Which one of the following on reduction with \(\mathrm{NaBH}_{4}\) gives an equimolar mixture of sorbitol and mannitol? (a) mannose (b) glucose (c) xylose (d) fructose

Which of the following compounds will not show mutarotation? (a) \(\beta-\mathrm{D}(+)\) glucopyranose (b) \(\alpha-\mathrm{D}(+)\) glucospyranose (c) \(\beta-\mathrm{D}(+)\) galactopyranose (d) methyl- \(\alpha\)-D-glucopyranoiside

The conversion of maltose to glucose is possible by the enzyme (a) zymase (b) lactase (c) maltase (d) diastase

Oxidation of fructose with bromine water gives (a) gluconic acid (b) oxalic acid (c) trimethyl glutaric acid (d) tartaric acid

Which of the following is known as leavulose sugar? (a) glucose (b) fructose (c) surcose (d) arabinose

Cellulose is a polymer of (a) glucose (b) fructose (c) ribose (d) sucrose

Basic solution of fructose contains (a) only glucose (b) only fructose (c) glucose, fructose and mannose (d) glucose and fructose

An alteration in the base sequence of nucleic acid molecule is (a) dislocation (b) replication (c) duplication (d) mutation

Fructose is ketose sugar, even then it gives red precipitate with Fehling solution because (a) keto sugars undergo transformation into aldose sugars in the presence of Fehling's solution (b) ketones are oxidized by Fehling solution (c) both (a) and (b) (d) none of these

Iodine test is shown by (a) starch (b) glycogen (c) polypeptides (d) glucose

Glucose reacts with acetic anhydride to form (a) hexa acetate (b) penta acetate (c) tri acetate (d) mono acetate

Carbohydrates are stored in human body as the polysaccharide (a) glycogen (b) glucose (c) starch (d) galactase

\(\alpha-\) and \(\beta\) - glucose differ in the orientation of \(-\mathrm{OH}\) group around (a) \(\mathrm{C}_{1}\) (b) \(\mathrm{C}_{2}\) (c) \(\mathrm{C}_{3}\) (d) \(\mathrm{C}_{4}^{2}\)

Reduction product of glucose is (a) menthol (b) sorbitol (c) mannitol (d) sorbitol and mannitol

Table sugar is (a) D-glucose (b) a disaccharide consisting of D-glucose and D-fructose (c) a monosaccharide (d) a disaccharide of D-glucose

An example of a sulphur containing amino acid is (a) lysine (b) serine (c) cysteine (d) tyrosine

Rapid interconversion of \(\alpha-\mathrm{D}\)-glucose and \(\beta-\mathrm{D}-\mathrm{glu}-\) cose in solution is known as (a) mutarotation (b) racemization (c) structural isomerisation (d) asymmetric induction

Water insoluble component of starch is (a) amylopectin (b) amylose (c) cellulose (d) none of these

The two structures of D-glucopyranose forms are (a) enantiomers (b) epimer (c) anomers (d) geometrical isomers

Enzymes are made up of (a) edible proteins (b) carbohydrates (c) nitrogen containing carbohydrates (d) proteins with specific structures

Which of the following is correct about enzymes? (a) it reduces the activation energy (b) it increases the activation energy (c) it changes the equilibrium constant (d) none of these

Which amino acid is achiral? (a) histidine (b) valine (c) proline (d) none of these

The helical structure of protein is stabilized by (a) ether bonds (b) peptide bonds (c) dipeptide bonds (d) hydrogen bonds

Fibrous protein are insoluble in (a) water (b) strong base (c) strong acid (d) both (b) and (c)

The \(\alpha\)-amino acid which contains an aromatic side chain is (a) proline (b) tyrosine (c) valine (d) tryptophan

Tertiary structure of protein contains which type of forces? (a) electrostatic, hydrogen bonds, van der Waals forces, dipole-dipole attractions and disulphide cross linkage (b) electrostatic, hydrogen bonds and van der Waals forces (c) electrostatic forces only (d) electrostatic as well as hydrogen bonds

Which of the following is an enzyme? (a) lipids (b) sucrose (c) emulsin (d) maltose

The enzyme which hydrolyses triglycerides to fatty acids and glycerol is called (a) pepsin (b) zymase (c) maltose (d) lipase

Lack of essential amino acids in the diet leads to the disease (a) Kwashiorkar (b) Sickle cell anaemia (c) Night blindness (d) Pernicious anaemia

Peptides are formed from (a) aliphatic amines (b) carbohydrates (c) \(\alpha\)-amino acids (d) aromatic amines

Which of the following amino acid is optically inactive? (a) phenyl amine (b) asparagine (c) glutamic acid (d) glycine

Primary structure of protein contains which type of bond? (a) only hydrogen (b) only covalent (c) only van der Waals (d) all of these

Strecker reaction is used for synthesis of (a) alcohol (b) amino acid (c) aldehyde (d) ketone

Denaturation of protein is caused by (a) addition of detergent (b) changing the \(\mathrm{pH}\) (c) addition of urea (d) all of these

The protein of the haemoglobin converts \(\mathrm{CO}_{2}\) of the tissues into (a) \(\mathrm{O}_{2}\) and \(\mathrm{C}\) (b) \(\mathrm{HCO}_{3}^{-}\)and \(\mathrm{Fe}^{2+}\) (c) \(\mathrm{O}_{2}\) and \(\mathrm{CO}\) (d) \(\mathrm{HCO}_{3}^{-}\)and \(\mathrm{H}^{+}\)

Which sugar is present in DNA? (a) purine only (b) deoxyribose (c) ribose (d) pyrimidine only

Which of the following is not present in a nucleotide? (a) cytosine (b) guanine (c) adenine (d) tyrosine

A sequence of how many nucleotides in messenger RNA makes a codon for an amino acid? (a) one (b) two (c) three (d) four

Which base is present in RNA but not in DNA? (a) uracil (b) thymine (c) cytosine (d) guanine

Glycosamine unit is present in (a) heparin (b) nucleic acid (c) chitin (d) all of these

Which of the following biomolecules contain nontransition metal ion? (a) vitamin \(\mathrm{B}_{12}\) (b) chlorophyll (c) haemoglobin (d) insulin

The coordination number of \(\mathrm{Fe}(\mathrm{II})\) in oxyhaemoglobin is (a) 10 (b) 8 (c) 6 (d) 4