1. 4.1: Exchange with the Environment
Cell Transport
EQ: Explain how cells take in nutrients and expel wastes.

2. What is Diffusion?
Diffusion: the movement of particles from areas of high concentration/density to areas of low concentration/density. (crowded to less crowded) Does NOT require energy.

3. Diffusion of Water Osmosis: The diffusion of water
Semipermeable membrane – only some substances can pass through
Cell membrane
Osmosis helps keep things in balance

4. Moving Small Particles
Active Transport
Passive Transport
the movement of particles from low to high concentration
REQUIRES energy
the movement of particles from high to low concentration
Does NOT require energy
Diffusion & Osmosis

5. How do small particles move across the cell membrane?
Through channels
Channels: passageways in the cell membrane that allow particles through.

6. Moving Large Particles
Endocytosis
Exocytosis
the movement of large particles into a cell.
Both require energy therefore are considered ACTIVE TRANSPORT.
The movement of large particles out of the cell
Vesicle – a sac that forms from pieces of the cell membrane.
Carry the particles