the roles of membranes within cells and at the surface of cells
*To include the roles of membranes as,
the fluid mosaic model of membrane structure and the roles of its components
To include phospholipids, cholesterol, glycolipids, proteins and glycoproteins AND the role of membrane-bound receptors as sites where hormones and drugs can bind.
(i) factors affecting membrane structure and permeability
To include the effects of temperature and solvents.
(ii) practical investigations into factors affecting membrane structure and permeability
PAG5, PAG8
(i) the movement of molecules across membranes
To include diffusion and facilitated diffusion as passive methods AND active transport, endocytosis and exocytosis as processes requiring adenosine triphosphate (ATP) as an immediate source of energy.
(ii) practical investigations into the factors affecting diffusion rates in model cells
PAG8
(i) the movement of water across membranes by osmosis and the effects that solutions of different water potential can have on plant and animal cells
Osmosis to be explained in terms of a water potential gradient across a partially-permeable membrane.
(ii) practical investigations into the effects of solutions of different water potential on plant and animal cells
PAG8