4. Cell membranes and transport Flashcards
describe the fluid mosaic model of membrane structure
S- hydrophobic and hydrophilic interactions account for the formation of the phospholipid bilayer and the arrangement of proteins.
arrangement of cholesterol, glycolipids and glycoproteins in cell surface membranes.
outline the main stages in the process of cell signalling leading to specific responses:
- secretion of specific chemicals (ligands) from cells.
- transport of ligands to target cells.
- binding of ligands to cell surface receptors on target cells.
describe the roles of phospholipids, cholesterol, glycolipids, proteins and glycoproteins in cell surface membranes
reference- stability, fluidity, permeability, transport (carrier
proteins and channel proteins), cell signalling (cell surface receptors) and cell recognition (cell surface antigens).
simple diffusion- describe and explain the process
facilitated diffusion- describe and explain the process
osmosis- describe and explain the process
active transport- describe and explain the process
endocytosis and exocytosis- describe and explain the process
investigate simple diffusion and osmosis using plant tissue and non-living materials, including dialysis (Visking) tubing and agar
illustrate the principle of surface area to volume ratios
investigate the effect of changing surface area to volume ratio
on diffusion using agar blocks of different sizes
surface area to volume ratios
decrease with increasing size.
diffusion decreases- more time.
investigate the effects of immersing plant tissues in solutions of different water potentials, using the results to estimate the water potential of the tissues
the more negative the water potential, the more concentrated it is.
explain the different effects of the
movement of water on plant cells and animal cells. dilute and concentrated
