1. Cell Transport
Semipermeable membrane – small, lipid-soluble particles can pass, but large, charged particles cannot
Diffusion – net movement of particles from high to low concentration
Concentration gradient – the difference in concentration between one area and another

2. Cell Membrane

3. Diffusion

4. Osmosis Diffusion of water through aquaporins
Moves from high water potential to low water potential.
Hypertonic solution – higher solute concentration
Hypotonic solution – lower solute conc.
Isotonic soln. – solute conc. Equal on both sides and equilibrium.

5. Osmosis

6. Facilitated Diffusion
Passive transport – no Energy required
Moves down concentration gradient
Moves through a carrier or channel protein
Ex. Glucose
Lipid-insoluble substances

7. Facilitated Diffusion

8. Active Transport Not passive
Goes up or against the concentration gradient (needs energy)
Na+ out/K+ in
Involves specific carrier proteins
Important in muscle contractions, nerve impulses – maintains resting potential
Ex. Plant roots, ion pumps

9. Active Transport – Sodium/Potassium Pump

10. Endocytosis Enodcytosis – cell taking materials in
Pinocytosis – cell drinking
Phagocytosis – cell eating

11. Endocytosis

12. Receptor-mediated endocytosis

13. Exocytosis Releasing molecules into the extracellular matrix
Bulk flow – passage of substances through vessels or xylem/phloem

14. Exocytosis

15. Cell Junctions Plasmodesmata – tunnels between plant cells
Junctions in animal cells – tight, anchoring, communicating

16. Tight, Anchoring and Communicating Junctions