Which one of the following vitamins contains a metal atom?

1. Riboflavin

2. Vitamin B₁₂

3. Vitamin A

4. Vitamin B₆

Adenosine is an example of:

(1) nucleotide

(2) nucleoside

(3) purine base

(4) pyrimidine base

In both DNA and RNA heterocyclic base and phosphate ester linkages are at:
1. \(C^1_5\) and \(C^1_2\) respectively of the sugar molecule.
2. \(C^1_2\) and \(C^1_5\) respectively of the sugar molecule.
3. \(C^1_1\) and \(C^1_5\) respectively of the sugar molecule.
4. \(C^1_5\) and \(C^1_1\) respectively of the sugar molecule.

Which one of the following statements is correct ?

1. All amino acids are optically active

2. All amino acids except glycine are optically active

3. All amino acids except glutamic acid are optically active

4. All amino acids except lysine are optically active

α-D-glucose and β D-glucose have a specific rotation of +112° and +19° respectively. In aqueous solution the rotation becomes +52°. This process is called:

(1) inversion

(2) racemisation

(3) mutarotation

(4) enolisation

The incorrect statement among the following is:

The central dogma of molecular genetics states that the genetic information flows from
(1) amino acids $\to$ proteins $\to$ DNA

(2) DNA $\to$ carbohydrates $\to$ proteins

(3) DNA $\to$ RNA $\to$ proteins

(4) DNA $\to$ RNA $\to$ carbohydrates

The correct corresponding order of names of four aldoses with configuration given below

respectively, is
1. L-erythrose, L-threose, L-erythrose, D-threose

2. D-threose, D-erythrose, L-threose, L-erythrose

3. L-erythrose, L-threose, D-erythrose, D-threose

4. D-erythrose, D-threose, L-erythrose, L-threose

In a protein molecule, various amino acids are linked together by

(1) b-glycosidic bond

(2) peptide bond

(3) dative bond

(4) a-glycosidic bond

The correct statement regarding RNA and DNA, respectively is: