BIOL 1001 Chapter : Chapter 5
Document Summary
The cell membrane is usually the outermost barrier of the cell: screen wall small things can pass, larger things cannot. An exception to this is found in cells which have a cell wall plants - cellulose fungi - chitin bacteria - chitin plus proteins. The cell wall is mainly for structural support and protection: it usually doesn"t act as a barrier to molecules. The plasma membrane: the plasma membrane contains the cell but still allows the cell to interact with the environment. The plasma membrane functions: isolate the cell environment. Keep things from leaking into and out from the cell at will. Allows chemical reactions to take place without interference: regulate exchange between inside and outside, communicate with other cells, identify the cell type important to immune system. Protein patterns on membrane not recognized are attacked by immune system. Cell identification contact. not present on skin cells.
