A heart attack happens when blood flow to the heart suddenly. becomes blocked and the heart canât get oxygen. quickly, the heart muscle fails to pump and begins to die. disease (CHD), also called coronary artery disease.
The B-cell receptor is composed of two parts: i) A membrane-bound immunoglobulin molecule of one isotype (IgD, IgM, IgA or IgE).he B-cell receptor is composed of two parts: i) A membrane-bound immunoglobulin molecule of one isotype (IgD, IgM, IgA or IgE).
G-protein-coupled receptors (GPCRâs): these are the largest of all the cell surface receptors. They activate membrane-bound, trimeric GTP binding proteins (G-proteins) which then activate either an enzyme or an ion channel (effector) in the plasma membrane, initiating a sequence of other effects.ell surface receptors are responsible for the binding of an extracellular signalling molecule and transduction of its messages into one or more intracellular signalling molecules, which changes the cellâs behaviour. A cell surface receptor exists intrinsically embedded in the plasma membrane.