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.
A co-receptor is a cell surface receptor that binds a signalling molecule in addition to a primary receptor in order to facilitate ligand recognition and initiate biological processes, such as entry of a pathogen into a host cell.n immunology in particular, the term co-receptor often describes a secondary receptor used by a pathogen to gain access to the cell, or a receptor that works alongside T cell receptors such as CD4, CD8, or CD28 to bind antigens or regulate T cell activity in some way.
photoreceptors and chemoreceptors: They are modular in their architecture, and each module is associated with a different aspect of receptor function (110). A photoreceptor typically com-prises several discrete protein units known as modules or domains, each of which forms a co-valentlyconnected,compactlyfoldedportionof the sequence.