Diffusion and Active Transport

• What is the primary function of the cell membrane in relation to substances?

  It allows substances to move in and out of cells.
• What are the two ways substances can move through the cell membrane?

  Diffusion and active transport.
• What is the direction of movement in diffusion?

  From higher to lower concentration.
• What is diffusion?

  • The movement of particles from areas of high concentration to areas of low concentration.
  • It is a gradual process.
  • It occurs until equilibrium is reached.
• What does diffusion involve in terms of particle concentration?

  It involves the movement from places where there are lots of particles to places where there are fewer particles.