Answer
Receptors, or transmembrane receptors, are surface proteins made specifically for one type molecule that binds to transmit an intracellular signal. Pumps, are type of carriers that require energy in the form of ATP to transports molecules from one side of the membrane to the other. Cell-adhesion molecules are proteins in the surface of the cell that allow for the process of cell adhesion to take place.
Work Step by Step
Most of the time, molecules can't pass through the plasma membrane without the help of a receptor, a protein in the cell membrane that enables a specific molecule to enter the cell. There are two main types of receptors: internal receptors and cell-surface receptors. Cell-surface receptors allow for the transduction of extracellular signals to intracellular messages. Pumps, are forms of carriers that move molecules against their chemical gradients, that is from an area of low concentration to one of high concentration, in a process called active transport. The most famous example of a pump is the sodium-potassium pump, which is involved in neural impulses. Cells usually can't grow or survive unless they are attached to extracellular materials. The process of binding to other cells, or extracellular material is known as cell adhesion, and it is carried out by proteins in the surface of the cell known as cell-adhesion molecules.
