1. 7.3 Cell Structure Cell Transport Movement of materials
Occur at boundaries (membranes)
Two major types:
Passive
Active

2. Passive Transport Movement without the use of cellular energy
Diffusion-particles move from high concentration to low concentration (any material)
Equilibrium - equal concentration on both sides of the membrane

3. Facilitated diffusion-large molecules need help to travel across the membrane
Uses protein channels
Osmosis - diffusion of water
Isotonic-diffusion of water
Hypertonic - more
Hypotonic - less

4. Active Transport Movement against a concentration gradient
Requires energy
Carried out by protein pumps
Two processes that transport larger
molecules
Endocytosis — entering the cell
Exocytosis — exiting the cell

5. Structure of the Cell Membrane
Double layer (called lipid bilayer)
Provides flexibility
Lipids in membrane have two parts
Hydrophilic (water loving heads)
Hydrophobic (water fearing tails)