The couplings between base units of DNA is through : 

1.	Hydrogen bonding	2.	Electrostatic bonding
3.	Covalent bonding	4.	Van der waal's forces

The segment of DNA which acts as the instrumental manual for the synthesis of the protein is 

1. nucleotide

2. ribose

3. gene

4. nucleoside

Which of the following structures represents the peptide chain ?

1. 

2. 

3. 

4. 

On hydrolysis of starch, we finally get

1. glucose

2. fructose

3. Maltose

4. Both 1 and 3

The correct option about the presence of  H-bond in nucleotides is: 

1. A-T, G-C

2. A-G, T-C

3. G-T, A-C

4. A-A, T-T

During the process of digestion, the proteins present in food materials are hydrolysed to amino acids. The two enzymes involved in the process

$\mathrm{Proteins} \stackrel{\mathrm{Enzyme} \left(\mathrm{A}\right)}{\to } \mathrm{Polypeptides}$
$\stackrel{\mathrm{Enzyme} \left(\mathrm{B}\right)}{\to } \mathrm{Amino} \mathrm{acids},$

are respectively                

1. amylase and maltase

2. diastase and lipase

3. pepsin and trypsin

4. invertase and zymase

The helical structure of proteins is established by

1. dipeptide bonds

2. hydrogen bonds

3. ether bonds

4. peptide bonds

The a-D-glucose and b-D-glucose differ from each other due to difference in carbon atom with respect to its

1. conformation

2. configuration

3. number of OH-groups

4. size of hemiacetal ring

Glycolysis is

1. oxidation of glucose to pyruvate

2. conversion of glucose to haem

3. oxidation of glucose to glutamate

4. conversion of pyruvate to citrate

Sucrose in water is dextrorotatory, ${\left[\mathrm{\alpha }\right]}_D=+66.4°$ when boiled with dil.HCl, the solution becomes leavorotatory, ${\left[\alpha \right]}_D=-39.9°.$ In this process the sucrose breaks into

1. L-glucose + D-fructose

2. L-glucose + L-fructose

3. D-glucose + D-fructose

4. D-glucose + L-fructose