Lesson 46 - Antibodies

Question 1

Antibody definition

Answer 1

A protein with specific binding sites complementary to a specific antigen, synthesised and secreted by plasma cells.

Question 2

Describe the structure of an antibody

Answer 2

4 polypeptide chains (2 heavy and 2 light)
Constant region
Variable region with antigen binding sites
4 disulfide bridges

Question 3

Explain why an antibody binds to a specific antigen? (3 marks)

Answer 3

1. Antibody/variable region has a specific amino acid sequence;
2. The tertiary structure of the binding site is complementary to these antigens;
3. Forms antigen-antibody complex;

Question 4

What is agglutination?

Answer 4

When antibodies each bind to an antigen on 2 separate pathogens, causing the pathogens to clump together via a network of antigen-antibody complexes.
This clump is easier for for phagocytes to locate and engulf.

Question 5

What are monoclonal antibodies?

Answer 5

Antibodies with the same tertiary structure produced from a genetically identical set of plasma cells are referred to as monoclonal. They’re all specific to the same antigen.