Question

During diffusion, do molecules move from areas of low concentration to high concentration, or high concentration to low concentration? What about during active transport?

Answer 1

1) Diffusion is the move of molecules from high to low concentration.
Molecules move with the concentration gradient (high -> low) in diffusion until concentration is uniform. One example is osmosis - the movement of water.

2) Active transport is the move of molecules from low to high concentration.
This kind of transport requires energy to move against the concentration gradient (low -> high). Think: being "active" requires energy.