Variable regions

Definition

Variable regions are the parts of an antibody's structure that vary between different antibodies and are responsible for antigen binding. These regions determine the specificity and diversity of the immune response.

5 Must Know Facts For Your Next Test

1. Variable regions are located on both the heavy and light chains of an antibody.
2. They form the antigen-binding site through hypervariable loops, also known as complementarity-determining regions (CDRs).
3. The specific amino acid sequence in variable regions allows antibodies to recognize a vast array of antigens.
4. Monoclonal antibodies have identical variable regions, while polyclonal antibodies have diverse variable regions due to their production from multiple B cells.
5. The genetic recombination process called V(D)J recombination is responsible for generating the diversity in variable regions.

Review Questions

• Where are the variable regions located on an antibody?
• What role do complementarity-determining regions (CDRs) play in an antibody's function?
• How does V(D)J recombination contribute to the diversity of variable regions?

Related terms

Antigen: A molecule or molecular structure that can be bound by an antibody or T-cell receptor.

Monoclonal Antibody: An antibody produced by a single clone of cells, all with identical specificity.

Polyclonal Antibody: A mixture of antibodies produced by different clones of B cells, each recognizing different epitopes on an antigen.