Identify the incorrect statement regarding the structure of proteins:

1. They are heteropolymers containing strings of amino acids.

2. The first amino acid in the primary structure is the N-terminus amino acid

3. Only left helices are observed in proteins

4. Tertiary structure is absolutely essential for many biologic functions of the proteins

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

1. 3.4$°$

2. 34$°$

4. 3.6$°$

4. 36$°$

The blood concentration [in mM] of glucose in a normal healthy individual is:

1.  4.5$-$5.0

2.  5.0$-$5.5

3.  5.5$-$6.0

4.  6.0$-$6.5

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.

The tail of the phospholipid molecule:

1. is hydrophilic and composed of phosphate

2. is hydrophilic and composed of saturated hydrocarbons

3. is hydrophobic and composed of saturated hydrocarbons

4. is hydrophobic and composed of unsaturated hydrocarbons

In animal cells, lipid-like steroidal hormones are synthesized in the:

1. Nucleus

2. Rough endoplasmic reticulum

3. Smooth endoplasmic reticulum

4. Golgi apparatus

Lignin is a component of the secondary walls of:-

1. Epidermis

2. Collenchyma

3. Sclerenchyma

4. Parenchyma

Given below is the graph showing the effect of substrate concentration on enzyme activity. In the presence of a competitive inhibitor, when the concentration of the substrate is progressively increased :

1. The ${\mathrm{K}}_{\mathrm{m}}$ value is increased but the reaction will not achieve ${\mathrm{V}}_{\max }$

2. The ${\mathrm{K}}_{\mathrm{m}}$ value is increased but the reaction can ultimately achieve ${\mathrm{V}}_{\max }$

3. The ${\mathrm{K}}_{\mathrm{m}}$ value is decreased but the reaction will not achieve ${\mathrm{V}}_{\max }$

4. The ${\mathrm{K}}_{\mathrm{m}}$ value is decreased but the reaction can ultimately achieve ${\mathrm{V}}_{\max }$