1. Cell Transport Ch. 7.3 & 7.4

2. Plasma Membrane Membrane Lipids
Cell membranes consist of a phospholipid bilayer

3. Plasma Membrane Membrane Proteins
Cell membranes often contain proteins embedded within the phospholipid bilayer.

4. Plasma Membrane Fluid Mosaic Model
the phospholipid bilayer behaves like a fluid more than it behaves like a solid.

5. Diffusion Chapter 4 Diffusion
the movement of a substance from an area of high concentration to an area of lower concentration
caused by the random motion of particles of the substance

7. concentration gradient
passive transport
movement across the cell membrane that does not require energy
concentration gradient
A difference in the concentration of a substance, across a space

8. Equilibrium equilibrium
the concentration of a substance is equal throughout a space

9. Some substances move across the cell membrane without any use of energy by the cell.

10. Simple Passive Diffusion
Many substances enter or leave cells by diffusing across the cell membrane.

11. Osmosis Chapter 4 osmosis
the diffusion of water through a selectively permeable membrane
determined by solute concentration on both sides of the cell

12. Osmosis is a type of passive transport

13. There are three possibilities for the direction of water movement:

14. Osmosis Chapter 4 Hypertonic solution
solute concentration outside the cell is HIGHER THAN the cytosol
there is a NET movement of water out of the cell.
the cell shrinks.

15. Osmosis Hypotonic solution
solute concentration outside the cell is LOWER THAN the cytosol
there is a NET movement of water into the cell.
the cell swells.

16. Osmosis Isotonic solution
the solute concentration outside the cell is EQUAL TO the cytosol
there is no NET movement of water.

17. Compare

18. Facilitated Diffusion
Passive transport across the membrane using an embedded protein

19. Carrier proteins
bind to a specific substance on one side of the cell membrane, carry the substance across the cell membrane, and release it on the other side.

20. a transport protein with a polar pore through which ions can pass.
Ion channel
a transport protein with a polar pore through which ions can pass.

21. Movement Against a Concentration Gradient
active transport
the transport of a substance across the cell membrane against its concentration gradient. Energy is required.

22. Comparing Active and Passive Transport

23. Movement in Vesicles endocytosis
The movement of larger substances across the cell membrane by vesicles.

25. exocytosis
the movement of a substance by a vesicle to the outside of a cell