What is an example of diffusion?

3.1.1 Define diffusion as the net movement of particles from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement

3.1.2 Describe the importance of diffusion of gases and solutes

3.1.3 State that substances move into and out of cells by diffusion through the cell membrane

3.1.4 State that the energy for diffusion comes from the kinetic energy of random movement of molecules and ions

3.1.5 Investigate the factors that influence diffusion, limited to surface area, temperature, concentration gradients and distance

3.2.1 State that water diffuses through partially permeable membranes by osmosis

3.2.10 Explain the importance of water potential and osmosis on animal cells and tissues

3.2.11 Explain how plants are supported by the turgor pressure within cells, in terms of water pressure acting against an inelastic cell wall

3.2.2 State that water moves in and out of cells by osmosis through the cell membrane

3.2.3 Investigate and describe the effects on plant tissues of immersing them in solutions of different concentrations

3.2.4 State that plants are supported by the pressure of water inside the cells pressing outwards on the cell wall

3.2.5 State that plants are supported by the pressure of water inside the cells pressing outwards on the cell wall

3.2.6 State that plants are supported by the pressure of water inside the cells pressing outwards on the cell wall

3.2.7 Define osmosis as the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane

3.2.8 Explain the effects on plant tissues of immersing them in solutions of different concentrations by using the terms turgid, turgor pressure, plasmolysis and flaccid

3.2.9 Explain the importance of water potential and osmosis in the uptake of water by plants

3.3.1 Define active transport as the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration

3.3.2 Define active transport as the movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration using energy from respiration

3.3.3 Discuss the importance of active transport as a process for movement across membranes: – e.g. ion uptake by root hairs and uptake of glucose by epithelial cells of villi and kidney tubules

3.3.4 Explain how protein molecules move particles across a membrane during active transport