Combined ScienceCode 5129
Movement into and out of cells
What this topic asks you to be able to do
- Outline what water does as a solvent within living things, relating this to digestion, excretion and transport
- Understand diffusion as molecules or ions spreading out through their random movement, so that there is a net movement from where their concentration is higher to where it is lower (i.e. down a concentration gradient)
- Outline how surface area, temperature, concentration gradients and distance each influence how quickly diffusion occurs
- Understand osmosis as water molecules making a net movement across a partially permeable membrane, from where the water potential is higher to where it is lower (working out water potential values is not required)
- Describe how osmosis affects plant and animal tissues, and explain why the water potential gradient and osmosis matter when water is taken up and lost
- Investigate and account for how plant tissues are affected when placed in solutions of differing concentrations, using the terms turgid, turgor pressure, plasmolysis and flaccid