PSL201Y1 Lecture : Intercellular Communication I
Document Summary
Intercellular communication i: factors affecting the direction of transport, rate of transport, passive transport, active transport, osmosis: passive transport of water across membranes, transport of material within membrane bound compartments, epithelial transport: movement of molecules across two membranes. Membranes act as a barrier to separate the icf from the ecf and restricts the passage of movement of material. The membrane also allows some materials to get through such as oxygen, carbondioxide, glucose etc. The membrane is selectively permeable, allowing some things to go through but not others. The definition of membrane permeability is that if a substance can cross a membrane, by any means, the membrane is set to be permeable to that substance. In order to live, cells must be able to execute exchanges with its environment. For example, since all cells require oxygen and need to get rid of carbondioxide, small molecules must be able to move across the membrane to transport things from and to the cell.
