The processing requirements include successful completion of: 1  The application process, which includes a background and polygraph examination, a medical examination, a physical fitness evaluation, and a written examination; 2  24-26 weeks of intensive Academy training.
The cell membrane, being exposed to the outside environment, is an important site of cell-cell communication. As such, a large variety of protein receptors and identification proteins, such as antigens, are present on the surface of the membrane.
The seven-transmembrane Î±-helix structure of a G-protein-coupled receptor. Cell surface receptors (membrane receptors, transmembrane receptors) are receptors at the surface of a cell (built into its cell membrane) that act in cell signaling by receiving (binding to) extracellular molecules.