BIOL 1001 Chapter : Chapter 5 Biology
Document Summary
The cell membrane is usually the outermost barrier of the cell: an exception of 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 doesn"t usually 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, fig. 4. 2: the four plasma membrane functions, isolate the cell environment, regulate exchange between inside and outside, communicate with other cells, identify the cell type-allows the cell to identify things that are not cells (viruses etc. ) Cell identification: membrane proteins provide a fingerprint" for the cell type, hiv binds to cell receptors that are present on cells inside the body, but not present on skin cells. Called cd receptors (cluster of differentiation): this is why it is unlikely that you will contract hiv through causal contact.
