Bio 9 : Passive transport

1. Passive transport is the movement of substances across the plasma membrane from a region of high concentration to a low concentration.

2. In passive tramsport, the substances move down their concentration gradient and therefore do not require energy.

3. Substances move across the plasma membrane down the concentration gradient through 3 ways :
~lipid bilayer
~pore protein
~ carrier protein.

4. Substances can move freely without using energy across the membrane through simple diffusion or with the help of tramsport proteins in the membrane through facilitated diffusion.