Cell Transport Study Guide

1. Which forms of transport do NOT require energy? Diffusion Osmosis Facilitated Diffusion *All of these are passive!

2. Which forms do require energy? Endocytosis Exocytosis Sodium-Potassium Pump *All of these are active!

3. At the end of the diffusion process, the concentration of substances on each side is _____________. Equal

4. Draw an illustration of diffusion. On right side of board. Sugar molecules start out lumped together and gradually move until they are evenly spread out.

5. Define diffusion. Movement of molecules from an area of high concentration to an area of low concentration.

6. Red blood cells have a salt concentration of 0.9% In a solution of 1.2% salt, they will shrink because water moves out of the cell. In a 0.9% saline solution, they will remain the same because the two are equal. In pure water, they will swell because water will move into the cell.

7. Define osmosis. Diffusion of water molecules.

8. In the diagram, which direction will the substances move? From left to right (high conc. to low conc.)

10. A cell will swell when it is placed in a __________ solution. hypotonic

11. A cell will shrink when placed in a _____________ solution. hypertonic

12. A cell will remain the same when placed in an ___________ solution. isotonic

13. What is the difference between active and passive transport? Active requires energy and moves molecules against their concentration gradient. Passive does not require energy and moves molecules down their concentration gradient.

14. Proteins that act like selective passageways in the cell membrane are known as ___________. Channel proteins

15. What kind of molecules can pass through the cell membrane unaided? Small, nonpolar

16. During the egg demo, the egg gains mass and became swollen 16. During the egg demo, the egg gains mass and became swollen. What is the explanation for this? It was placed in a hypotonic solution and water moved into the egg.

17. What is the energy source for active transport? ATP

18. Molecules that are too large to be moved through the membrane can be transported into the cell by _______. Endocytosis

19. Ridding the cell of materials by discharging the materials in vesicles is called ______________. Exocytosis

20. Describe the Sodium-Potassium pump. What type of transport is it? A protein in the cell membrane that moves Na and K ions against their concentration gradient. It requires ATP, so it is active transport.

21. Describe the lipid bilayer. Drawing on board! It is a double layer of phospholipids arranged tail to tail, making up the cell membrane.

22. Define concentration gradient. A difference in concentrations.

23. What is equilibrium? Balance

A cell membrane is ______ permeable because it allows for the passage of some substances but not others. Semi or selectively