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.
CHAPTER 24 Plasma Membrane Receptors. Cells use about 20 different families of receptor proteins to detect and respond to the myriad of incoming chemical and physical stimuli (Appendix 24-1). Most receptors are plasma membrane proteins that interact with chemical ligands or are