Plasma Membranes

This PowerPoint relates to the Plasma Membranes section of the BY1 specification. Students learn about the:

(a) Principal components of the plasma membrane and the fluid mosaic model. Factors affecting permeability of the membrane.

(b) Transport mechanisms: diffusion and factors affecting the rate of diffusion, osmosis and water potential, pinocytosis, facilitated diffusion, phagocytosis, secretion (exocytosis), active transport and influence of cyanide.

Suggested Practical activities:

Determination of water potential by measuring changes in mass, and solute potential by measuring the degree of incipient plasmolysis. Permeability of cell membranes using beetroot.

Plasma membranefluid mosaic modelpermeabilitydifusionosmosiswater potential