Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
B Cell Receptor (BCR) is a membrane-bound immunoglobulin molecule present on the surface of B lymphocytes. It plays a crucial role in recognizing specific antigens and initiating an immune response.
5 Must Know Facts For Your Next Test
BCRs are essential for the activation and differentiation of B cells.
Each B cell has a unique BCR that is specific to a particular antigen.
Upon binding to an antigen, the BCR triggers intracellular signaling pathways leading to B cell activation.
BCRs undergo somatic hypermutation and class-switch recombination during an immune response to increase antibody diversity.
The structure of a BCR includes two heavy chains and two light chains forming a Y-shaped molecule.