What's the difference between active and passive transport?
Short story: Active transport uses energy, passive transport doesn't.
Long story: For almost all substances, there is a difference in concentration of substances inside and outside of the cell. This is called a concentration gradient. Substances naturally move from high concentration to low concentration so passive transport is usually good enough to get these substances in or out of cells. Some cells use facilitated diffusion to help materials move in or out. Facilitated diffusion is "facilitated" by a protein in the plasma membrane which lets a certain molecule pass through easily while keeping others out. If substances need to be moved from low to high concentration, the cell has to use energy and a specially designed protein (usually called a "pump") to move the substances against the concentration gradient.
The videos below show animations of the various types of transport. Please pick one of them and watch it to visually see how active and passive transport work.
Long story: For almost all substances, there is a difference in concentration of substances inside and outside of the cell. This is called a concentration gradient. Substances naturally move from high concentration to low concentration so passive transport is usually good enough to get these substances in or out of cells. Some cells use facilitated diffusion to help materials move in or out. Facilitated diffusion is "facilitated" by a protein in the plasma membrane which lets a certain molecule pass through easily while keeping others out. If substances need to be moved from low to high concentration, the cell has to use energy and a specially designed protein (usually called a "pump") to move the substances against the concentration gradient.
The videos below show animations of the various types of transport. Please pick one of them and watch it to visually see how active and passive transport work.
|
|
For the information where you can read it, go here: http://www.diffen.com/difference/Active_Transport_vs_Passive_Transport