Download Cell Transport – Review Sheet

Cell Transport – Review Sheet
1. What are two functions of the cell membrane?
Controls what goes in and out of the cell to maintain homeostasis
2. How does the cell membrane help maintain homeostasis?
It makes sure that the required materials can get in and the materials that need to leave can get
out
3. Why is the fluid environment of the cell and its surroundings important to its function?
The fluid environment allows materials such as nutrients, oxygen and wastes move into or out of
the cell
4. What does it mean that the membrane is selectively permeable?
The membrane allows some molecules to enter the cell and keeps others out
5. What are the two types of transport?
Passive and active
6. What are the two main differences between the two types of transport?
Passive does not use energy and active does. Passive transports materials from high
concentration to low while active transports from low to high concentrations.
7. What are the three types of passive transport?
Diffusion, Facilitated diffusion, and osmosis
8. What are the three types of active transport?
Protein pumps, endocytosis, and exocytosis
9. In which type of transport do molecules move randomly?
passive
10. In which type of transport do molecules move actively?
active
11. In passive transport, molecules move from areas of ______ concentration to areas of ________
concentration.
High, low
12. In active transport, molecules move from areas of ______ concentration to areas of ________
concentration.
Low, high
13. What is diffusion?
Random movement of particles from areas of high concentration to areas of low concentration
14. Diffusion continues until __________________ when molecules are still __________ but stay
________________.
Equilibrium, moving, spread out
15. What is facilitation diffusion?
Diffusion of specific particles through transport proteins found in the membrane
16. How do transport proteins work?
They “select” specific molecules to help pass through the membrane
17. What types of molecules would typically be transported by facilitated diffusion?
Large or charged particles
18. In facilitated diffusion, molecules move from areas of ______ concentration to areas of ________
concentration.
High, low
19. What is osmosis?
Diffusion of water through a selectively permeable membrane
20. In osmosis, _____________ moves from areas of ______ concentration to areas of ________
concentration.
Water, high, low
21. Why can a cell not control the movement of water?
It is so abundant and so small that it moves across the membrane out of the cell’s control
22. Define solute and solvent.
Solute: what is being dissolved
Solvent: what dissolves the solute
23. A solution that has a lower concentration of solutes and a higher concentration of water than inside
the cell is _________________.
hypotonic
24. A solution that has a higher concentration of solutes and a lower concentration of water than inside
the cell is _________________.
hypertonic
25. A solution that has an equal concentration of solutes outside and inside the cell is
_________________.
isotonic
26. What would happen to a cell that is placed in a hypotonic solution? What is that called?
Water moves into the cell and the cell swells or bursts; lysis
27. What would happen to a cell that is placed in a hypertonic solution?
Water moves out of the cell and cell shrinks
28. What happens when a cell is placed in an isotonic solution? What is that called?
Water moves equally in and out and cell stays the same size; dynamic equilibrium
29. What prevents bacteria and plant cells from over-expanding?
The cell wall
30. What is turgor pressure?
The pressure exerted on the cell wall by the water inside the cell
31. How do protists control water in their cells?
The pump in or expel water with contractile vacuoles
32. How do fish control the concentration of salt in their cells?
They pump salt out of their specialized gills so they do not dehydrate
33. What organs do humans use to remove excess salts and water?
kidneys
34. A cell has 20% salt and 80% water is in a solution that has 10% salt and 90% water.
a. In what type of solution is the cell? hypotonic
b. Where will water move? Into the cell
c. What will happen to the cell? cell swell and/or burst (lyse)
35. A cell has 20% salt and 80% water is in a solution that has 30% salt and 70% water.
a. In what type of solution is the cell? hypertonic
b. Where will water move? Out of the cell
c. What will happen to the cell? Cell with shrink
36. A cell has 20% salt and 80% water is in a solution that has 20% salt and 80% water.
a. In what type of solution is the cell? isotonic
b. Where will water move? In and out of the cell equally
c. What will happen to the cell? It will reach dynamic equilibrium and stay the same size
37. What are protein pumps?
Transport proteins within the cell membrane that require energy to do work
38. Give an example of a protein pump.
Sodium/potassium pump
39. Protein pumps change _________ and require __________.
Shape, energy
40. Protein pumps move molecules from areas of ______ concentration to areas of ________
concentration.
Low, high
41. What is endocytosis?
Taking bulky material into a cell
42. Describe the process cells use to “eat”.
Cell membrane folds around a food particle and forms a food vacuole where the food is digested
43. What is exocytosis?
Membrane around the material fuses with the cell membrane and forces the material out of the
cell
44. What types of materials are commonly expelled by exocytosis?
Hormones, waste
45. Why does active transport require more energy than passive transport?
Passive transport goes with the concentration gradient while Active transport goes against the
concentration gradient. Going against the gradient (low  high) requires energy.