About 98% of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and:

(1) Phosphorous and sulphur

(2) Sulphur and magnesium

(3) Magnesium and sodium

(4) Calcium and phosphorous

In non-competitive inhibition:

1. the substrate and inhibitor cannot bind to the enzyme at the same time

2. the inhibitor binds only to the substrate-enzyme complex

3. the inhibitor can bind to the enzyme at the same time as the enzyme's substrate

4. the binding of the inhibitor to the enzyme reduces its activity but does not affect the binding of substrate

Which of the following elements is present in higher proportion [% weight of the total] in Earth's crust with respect to the average composition of a human body?

1. Carbon

2. Nitrogen

3. Sulfur

4. Magnesium

Identify the amino acid with hydroxymethyl as its R group:

1. Glycine

2. Alanine

3. Serine

4. Phenylalanine

All of the following are nucleosides, except:

Identify the incorrect statement regarding the structure of proteins:

At each step of its ascent, the DNA strand turns:

1. 3.4$°$

2. 34$°$

3. 3.6$°$

4. 36$°$

The substrate has to go through a much higher energy state or transition state in case of:

1. Exothermic reactions only

2. Endothermic reactions only

3. Both exothermic and endothermic reactions

4. Neither exothermic nor endothermic reactions

When the co-factor is removed from the enzyme, the catalytic activity:

1. is lost.

2. is reduced.

3. is increased.

4. is unaffected.

What is the term used for a protein molecule that assists in the proper folding of other proteins?

1. ubiquitin

2. chaperonin

3. vimentins

4. cyclins