Movement of Substances into and out of Cells(2Pages)

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-Diffusion is the process by which products move in and out of cells down a concentration gradient - from an area of high concentration to an area of low concentration.

-Osmosis is the movement of water molecules. from an area of high water potential to an area of low water potential, across a partially-permeable membrane

Active transport is the movement across a cell membrane from a lower to a higher concentration. In active transport, particles move against the concentration gradient - and therefore require an input of energy from the cell.

Turgid cells allow a plant to stand upright and allow leaves to spread out for photosynthesis. The cell wall stops them bursting

Factors affecting the rate of movement of Substances

-Thickness of membrane (distance)

-Surface area

-Concentration Gradient (difference in the two concentrations)

Osmosis Experiments

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