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.

The K_m value of an enzyme denotes the substrate concentration at which the enzyme catalyzed reaction:

1.  Reaches V_max

2.  Shows decline in the rate of reaction

3.  Attains ½ V_max

4.  Finally stops

Identify the given compound:

1.  An amino acid

2.  A purine base

3.  Polysaccharide containing nitrogen

4.  Prostaglandin

The “primary structure” of a protein refers to:

1. coiling due to hydrogen bonding between amino acids

2. the alpha helix or pleated sheets

3. the side groups of the amino acids

4. the number and sequence of amino acids

The monomer of nucleic acid is

1. nucleotides

2. nucleosides

3. nucleus

4. Both 1 and 2

How many types of nitrogenous bases are present in nucleic acid

1.4

2.3

3.5

4.6

How many of the following are purines?

Adenine, Uracil, Cytosine, thymine, Cysteine, threonine, Tryptophan, Guanine, Thymine

1.5

2.4

3.2

4.3

C’ represents carbon of

1.sugar of nucleotides

2.Nitrogenous bases of nucleotides

3.Both 1 and 2

4.None of the above