Give the plausible explanation for the following:
(i) Glucose doesn't give 2,4-DNP test.
(ii) The two strands in DNA are not identical but are complementary
(iii) Starch and cellulose both contain glucose unit as monomer. yet they are structurally different.

Given reason for the following : (i) Glucose does not give 2, 4 D.N.P. test or Schiff's reagent test. (ii) Amino acids have high melting points and are water soluble.

Explain the following : (i) Amino acids behave like salts rather than simple amines or carboxylic acids. (ii) The two strands of DNA are complementary to each other. (iii) Reaction of glucose that indicates the carbonyl group is present as an aldehydic group in the open structure of glucose.

(a) Despite having an aldehydic group, glucose does not give 2, 4-DNP test. What does it indicate ? (b) Draw Haworth structure of alpha-D(+) glucopyranose (c ) What is the significance of D and (+) here ?

(a) Give a plausible expianation for each one of the following : - (i) There are two - NH_(2) groupsin semicarbazide. However, only one such group is involvedin the formation of semicarbazones. (ii) Cyclohexanone forms cyanohydrin in good yield but 2,4,6 -trimethylcyclohexanone does not. (b) An organic compound with molecular formula C_(9)H_(10)O forms, 2,4 - DNP derivative, reduces Tollens' reagent and undergoes Cannizzaro reaction. On vigorous oxidation it gives 1,2-benzene-di-carboxylic acid. Identify the compound.

Giving plausible explanation for each of the following: i. Cyclohexanone forms cyanohydrin good yield but 2,2,6-trimethylcyclohexanone does not. ii. There are two (-NH_(2)) groups in semicarbazide. However, only one is involved in the formation of semicarbazones. iii. During the preparation of esters from a carboxylic acid and an alcohol in the ester should be removed as soon as it is formed.