unit 3 pp #9
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- 1. Cellular Transport
2. Energy-less Transport
- 1) Diffusion movement of substancesfrom a higher concentration to lower concentration
- The unequal distribution of particles is called a concentration gradient
- GOAL: EQUAL CONCENTRATION ON BOTH SIDES
- Osmosis: movement of water
3. Types of Solutions Inside Cell Outside Cell Movement Isotonic Solution Concentration inside and outside of the cell is equal Movement of material inside and outside of the cell is equal Hypotonic Solution More dissolved substances in the cell More water outside the cell Movement of water inside the cell (cell swells) Hypertonic Solution More water inside the cell More dissolved substances outside the cell Movement of water outside of the cell (cell shrinks) 4. Hypertonic Solution 5. Hypotonic Solution 6. Isotonic Solution 7. Energy-less Transport Cont.
- 2) Passive Transport movement of particles across the cell membrane
- a) Proteins special proteins
- (transport proteins) help larger
- substances move through the
- - Channel Proteins aqueous channel thatallows soluble material to pass into and out ofthe cell
- - called facilitated diffusion
- - driven by the concentration gradient
- - transport sugars and amino acids
8. Active and Passive Transport 9. Active Transport
- Requires energy
- Materials move against a concentration gradient
- Acts against diffusion
- Includes use of transport proteins
- Includes exocytosis and endocytosis
10. How does active transport work?
- A carrier protein binds with a particle of the substance to be carried across the membrane
- Moves the substance across based on charge and concentration (electrochemical gradient)
- When bonding has occurred, the chemical energy changes the shape of the carrier protein so that the particle is released into the cell
- Once released, the carrier protein regains its original shape
11. Active Transport 12. Gated Channels
- Involved in active transport
- Form a gate over certain pores.
- They are stimulated to open by a ligand, allowing substances to pass through.
13. Endo- and Exo- cytosis
- Endo in
- Cell surrounds and takes in material from the environment
- Creates a vacuole
- Vacuole is called a coated vesicle
- Exo out
- Expulsion or excretion of wastes, secretion of hormones
14. Endocytosis 15. Exocytosis 16.