- Dissolved substances move by diffusion and active transport.
- Water moves across boundaries by osmosis.
- Osmosis - diffusion of water from a dilute concentration to a more concentrated solution through a partially permable membrane that allows the passage of molecules.
- Differences in the concentrations of the solutions inside and outside of cells cause water to move in or out of a cell.
- Most soft drinks contain water, sugar and ions.
- Sports drinks contain sugars to replace sugar used in energy release in respiration during activity.
- Also contain water and ions to replace them when lost in sweating.