Question

Biochemistry:

For antibodies to be effective they must have specific antigen binding sites, each of which are created by a pocket in the tertiary structure. What are essential components of an effective antigen-binding pocket?
I. 1 heavy chain
II. 1 light chain
III. disulfide bonds that persist in a reducing environment
IV. sites at the N terminal end of a light chain that contribute to antigen binding
V. sites at the N terminal end of a heavy chain that contribute to antigen binding

	a.	I, II
	b.	I, II, III
	c.	I, II, IV
	d.	IV, V
	e.	III, IV, V
	f.	I, II, IV, V

Answer 1

Ans : f) I, II, IV, V

Antibody has two chains including heavy chain and light chains. The region in these chains are divided into variable and constant reagion. Variable region is the anitgen binding site which includes variable region of both heavy and light chains. It is made up of the N terminal region of the polypeptide. Constant regions donot bind to antigen but gives antibody the frame work and also determines antibody class. Disulfide bonds are found in the hinge region where the chains are joined and they are not found in antigen binding sites.