Passive transport
Passive transport is the movement of molecules across the plasma membrane down the concentration gradient without the input of energy[1].
There are two types of passive transport:
Non-polar, water, small, hydrophobic molecules can cross the membrane by simple diffusion
Many molecules (polar, charged, large, and hydrophilic) can not cross the plasma membrane, so the passage of these molecules is facilitated by membrane transport proteins (channel or carrier proteins)[2].
References:
- ↑ Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K. and Walter, P.(2002)Molecular Biology of the Cell, fourth edition, New York: Garland Science
- ↑ Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K. and Walter, P.(2002)Molecular Biology of the Cell, fourth edition, New York: Garland Science