Diffusion, osmosis and active transport

The idea

Diffusion is the net movement of particles from a higher to a lower concentration; it is faster with a steeper gradient, higher temperature and larger surface area. Osmosis is the diffusion of water from a dilute to a more concentrated solution through a partially permeable membrane. Active transport moves substances from a lower to a higher concentration, using energy from respiration.

1. Say which way the particles move compared with the gradient.
2. Say whether energy is needed.
3. For osmosis, name the membrane and the direction of water.

Watch out In osmosis, water moves towards the more concentrated solution (the one with less water).