An enzyme brings about:

(1) Decrease in reaction time

(2) Increase in reaction time

(3) Increase in activation energy

(4) Reduction in activation energy

The backbone of a DNA molecule is formed by:

A glycosidic bond connects:

The inhibition of succinic dehydrogenase by malonate is an example of:

The enzymes that catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds are called as:

The following diagram depicts the structure of a:

1. Nucleoside
2. Nucleotide
3. Nitrogen containing Monosaccharide
4. Glycoprotein

Which of the following is the simplest amino acid -

1. Alanine 

2. Asparagine

3. Glycine 

4. Tyrosine

Nucleotides are building blocks of nucleic acids. Each nucleotide is a composite molecule formed by -

1. Base-sugar-OH

2. Base-sugar-phosphate

3. Sugar-phosphate

4. (Base-sugar-phosphate)_n

The number of correct statements amongst the given statements is:

I. Amino acids are substitute methanes.

II. The R group in serine is hydroxyl-methyl.

III. Arachidonic acid has 20 carbon atoms including the carboxyl carbon.

IV. Glycerol is trihydroxypropane.

V. Lecithin is a phospholipid.

 1.  2     

 2.  3

 3.  4   

 4.  5

The following diagram shows the molecular structure of:

 1. A hexose sugar

 2. An aromatic amino acid

 3. A nitrogenous base found in RNA

 4. An important constituent of a DNA nucleotide.