BIOL 190 Lecture 9: 3/9 pt 1
Document Summary
Every cell is bordered by a plasma membrane. A barrier that prevents the diffusion of most material in/out of cell. Cho layer on external surface of cell. Blood type depends on the proteins and carbohydrates present on the surface. There are four primary types of membrane proteins, each forms a different function. Receptor proteins: bind to external chemicals in order to regulate processes within the cell. Recognition proteins: provide a fingerprint for the cell, so it can be recognized by other cells. Transport proteins: provide a passageway for molecules to travel into and out of the cell. Enzyme proteins: accelerate intracellular reactions on the plasma membrane. Functions of the plasma membrane: barrier, regulates transport, communication, recognition/ identification, anchor. Enzymes may be grouped to carry out sequential reactions. Receptor proteins relay the message by activating other molecules inside the cell. Attach to the extracellular matrix and cytoskeleton. Passive transport-- the spontaneous diffusion of molecules across a membrane.
