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Receptors meaning: A receptor is a molecule on the surface of a cell that recognizes and interacts with a specific molecule from outside the cell. Many receptors are proteins, but some are composed of other types of molecules.
Receptors in the immune system are proteins that recognize and bind to specific molecules on the surface of invading pathogens, such as bacteria or viruses. The receptors then trigger a response from the immune system that destroys the invading pathogens.
Types of Receptors
There are three types of receptors:
1. Cell-surface receptors: These are located on the cell surface and bind to hormones or other signaling molecules.
2. Intracellular receptors: These are located inside the cell and bind to hormones or other signaling molecules.
3. Nuclear receptors: These are located in the nucleus and bind to hormones and also other signaling molecules.
There are a variety of receptors that are located internally within the body. These receptors are responsible for detecting various stimuli, including chemicals, hormones, and nerve impulses, and then transmitting that information to the brain. Some of the most common internal receptors include the following:
1. Chemical receptors: These receptors are responsible for detecting chemicals that are present in the body, including hormones and neurotransmitters.
2. Hormonal receptors: These receptors are responsible for detecting hormones that are present in the body.
3. Nerve receptors: These receptors are responsible for detecting nerve impulses that are present in the body.
Cell-surface receptors are proteins that are embedded in the plasma membrane of cells. Therefore they are responsible for recognizing and binding to specific molecules that are present on the surface of other cells or on the surface of particles in the extracellular environment. This interaction between a receptor and its ligand initiates a cellular response.
T Cell Receptors
T Cell Receptors proteins found on the surface of T cells that recognize and bind to antigenic peptides presented by antigen-presenting cells. The T cell receptor consists of two chains, a heavy chain and a light chain, which are linked together by a disulfide bond. Each chain is composed of a variable region and a constant region. The variable region of the heavy chain is responsible for recognizing the antigenic peptide, while the variable region of the light chain is responsible for binding to the heavy chain.
B Cell Receptors
- B cells are lymphocytes that originate in the bone marrow and mature in the lymph nodes. They are responsible for the humoral immune response, which involves the production of antibodies that recognize and also bind to foreign antigens.
- B cells recognize antigens with the help of antigen-specific receptors on their surface. Therefore rhese receptors composed of two heavy chains and two light chains, which joined together by disulfide bonds. The heavy chains are responsible for antigen binding, while the light chains are responsible for signal transduction.
- When a B cell encounters an antigen, it binds to it with its antigen-specific receptor. This interaction activates the B cell and induces it to produce antibodies that recognize and bind to the antigen.