Exchange+with+the+Environment

What is diffusion?

Diffusion is the movement of particles and they travel between low concentrated areas and high concentrated areas. They tend to go to the lower concentrated areas. The diffusion in water is so important it has a special name which is omosis.

Moving Small Particles

Many particles can diffuse directly through the cell membrane. The particles slip through the membrane because of their small size. Not all particles can pass through the membrane this way. They must travel through protein "doorways" located in the cell membrane. Particles can travel through these proteins by active transport and passive transport. The cell does not need energry to allow passive transport to happen. For active transport to happen, the cell must use energy. The energy comes from the ﻿﻿ATP.

Moving Large Particles

The cell membrane has two ways of moving large particles: //endocytosis// and //exocytosis//.

