Archives: Questions and Answers

Explain the movement of water between cells and solutions in terms of water potential and explain the different effects of the movement of water on plant cells and animal cells (knowledge of solute potential and pressure potential is not expected)

Investigate the effects of immersing plant tissues in solutions of different water potentials, using the results to estimate the water potential of the tissues

Investigate the effect of changing surface area to volume ratio on diffusion using agar blocks of different sizes

Illustrate the principle that surface area to volume ratios decrease with increasing size by calculating surface areas and volumes of simple 3-D shapes (as shown in the Mathematical requirements)

Investigate simple diffusion and osmosis using plant tissue and non-living materials, including dialysis (Visking) tubing and agar

Describe the roles of phospholipids, cholesterol, glycolipids, proteins and glycoproteins in cell surface membranes, with reference to stability, fluidity, permeability, transport (carrier proteins and channel proteins), cell signalling (cell surface receptors) and cell recognition (cell surface antigens)

Investigate the progress of enzyme-catalysed reactions by measuring rates of formation of products using catalase and rates of disappearance of substrate using amylase

Investigate the difference in activity between an enzyme immobilised in alginate and the same enzyme free in solution, and state the advantages of using immobilised enzymes

State that enzymes are globular proteins that catalyse reactions inside cells (intracellular enzymes) or are secreted to catalyse reactions outside cells (extracellular enzymes)

Relate the structure of haemoglobin to its function, including the importance of iron in the haem group