Download Glucose plasma membrane homeostasis organism

Ch. 7-3 Review
Use each of the terms below just once to complete the passage.
Glucose
plasma membrane
homeostasis
organism
Name: ________________________
Period: ____
balance
selective permeability
Living cells maintain a (1)_________________________ by controlling materials that enter and leave. Without
this ability, the cell cannot maintain (2)____________________________ and will die. The cell must regulate internal
concentrations of water, (3)____________________, and other nutrients and must eliminate waste products. Homeostasis
in a cell is maintained by the (4)__________________________, which allows only certain particles to pass through and
keeps other particles out. This property of a membrane is known as (4)______________________________. It allows
different cells to carry on different activities within the same (5)___________________________.
For each statement, write “true” or “false.”
_____ 6. The structure and properties of the cell wall allow it to be selective and maintain homeostasis.
_____ 7. The plasma membrane is a bilayer of lipid molecules with protein molecules embedded in it.
_____ 8. A phospholipids molecule has a nonpolar water-insoluble head attached to a long polar, soluble tail.
_____ 9. The fluid mosaic model describes the plasma membrane as a structure that is liquid and very rigid.
_____ 10. Cell organelles, such as the nucleus, vacuoles, mitochondria, and chloroplasts, are enclosed by membranes.
_____ 11. The greater the number of saturated fatty acids a membrane contains, the more fluid it is.
_____ 12. In animals, cholesterol strengthens the fluid mosaic and makes the plasma membrane more stable.
Write the letter of the correct answer on the line.
____ 13. All objects in motion have:
A. potential energy
B. heat energy
C. kinetic energy
D. random energy
____ 14. Most of the cell and its surrounding environment are in a:
A. solid solution
B. gaseous solution
C. solid phase
D. water solution
____ 15. The net movement of particles from an area of higher concentration to an area of lower concentration is called:
A. active transport
B. nonrandom movement
C. osmosis
D. diffusion
____ 16. Diffusion occurs because of:
A. nonrandom movement of particles
C. random movement of particles
B. a chemical reaction between particles
D. chemical energy
____ 17. When a few crystals of potassium permanganate are dropped into a beaker of water, the ions of the dissolving
compound will:
A. move from low to high concentration
C. start to diffuse
B. form a polar bond
D. remain on the bottom of the beaker
____ 18. When materials pass into and out of the cell at equal rates, there is no net change in concentration inside the cell.
The cell is in a state of:
A. dynamic equilibrium
B. metabolism
C. imbalance
D. inertia
____ 19. Oxygen diffuses into the capillaries of the lungs because there is a:
A. lesser concentration of oxygen in the air sacs of the lungs than in the capillaries.
B. equal concentration of carbon dioxide in the air sacs of the lungs and the capillaries.
C. equal concentration of oxygen in the air sacs of the lungs than in the capillaries.
D. greater concentration of oxygen in the air sacs of the lungs than in the capillaries.
____ 20. The difference in concentration from one region to another is called:
A. dynamic equilibrium
B. concentration gradient
C. homeostasis
D. Brownian movement
____ 21. Molecules of the following will not diffuse directly across the lipid bilayer:
A. amino acids
B. carbon dioxide
C. water
D. oxygen
Complete the table by checking the correct column for each statement.
Statement
Isotonic Hypotonic Hypertonic
Solution Solution
Solution
22. The concentration of dissolved substances outside the cell is lower than inside
the cell.
23. When a cell is place in this solution, water will enter the cell by osmosis,
resulting in turgor pressure.
24. The concentration of dissolved substances outside the cell is the same as the
concentration inside the cell.
25. When injected into the body, it will not cause cellular damage because no
osmosis occurs.
26. Puttin a plant cell in this type of solution will result in a loss of water, and a drop
in turgor pressure (or plasmolysis), which will cause the plant to wilt.
27. The concentration of dissolved substances outside the cell is higher than the
concentration inside the cell.
Answer the following questions:
28. In a hypotonic solution, what type of pressure exists in a cell as the result of osmosis? What is the effect of this
pressure on non- woody plants? _____________________________________________________________________
__________________________________________________________________________________________________
29. What happens to plant when it is deprived of water or placed in a hypertonic environment? What is the process called?
__________________________________________________________________________________________________
__________________________________________________________________________________________________
Here are some lab reports. Assistance is needed. Write a response for each report.
LAB REPORT #30: Experiments show that lipid molecules can pass across the plasma membrane from an area of high
concentration to an area of lower concentration. By which process do the molecules move across the plasma membrane?
__________________________________
Does the cell expend energy? _____________ Explain: ____________________________________________________
__________________________________________________________________________________________________
LAB REPORT #31: A biochemical test shows the passive transport of sugar molecules into a muscle cell. What are the
proteins embedded in the lipid bilayer that aid in this movement called? _________________________ What are the two
main types? _______________________________ and __________________________
LAB REPORT #32: In a nerve cell, sodium ions move across the plasma membrane from an area of lower concentration
to an area of higher concentration. Does the nerve cell expend energy? ___________ What type of transport is taking
place? _____________________
LAB REPORT #33: An experiment reveals a carrier protein involved in active transport of an amino acid across
the membrane into a cell. Explain how the protein moves the molecule against a gradient.
__________________________________________________________________________________________
__________________________________________________________________________________________
Complete the table.
Type of solution:
Describe the effect of each
solution on a cell. (What will
happen to the cell when
placed in this type of
solution?)
Isotonic
34.
Hypertonic
35.
Hypotonic
36.
37. Freshwater protozoans, such as Paramecia, must constantly pump out water to keep from bursting (contracting
vacuole). What does this tell you about the solute concentration inside a Paramecia compared to the solute concentration
of its environment?
_________________________________________________________________________________________________
__________________________________________________________________________________________________
38. What would happen if you made the solute concentration outside the Paramecium the same as that inside it? _______
__________________________________________________________________________________________________
39. Complete the table by writing YES or NO in each square.
Active
Transport
Requires energy input.
40
Moves molecules against their concentration gradients. 43
Requires a membrane protein.
46
Sodium-potassium pump is an example.
49
Facilitated
Diffusion
41
44
47
50
Diffusion
42
45
48
51
52. Name a substance that can diffuse across the cell membrane: _______________________
53. Name a substance that is too large to diffuse across the cell membrane: ____________________
54. What prevents charged molecules from diffusing across the cell membrane? _________________________________
55. How is facilitated diffusion similar to simple diffusion? __________________________________________________
56. How is facilitated diffusion different from simple diffusion? ______________________________________________
57. How is facilitated diffusion similar to active transport? __________________________________________________
58. How is facilitated diffusion different from active transport? _______________________________________________
59. Briefly describe the action of the sodium-potassium pump: _______________________________________________
__________________________________________________________________________________________________
60. How are endocytosis and exocytosis similar? __________________________________________________________
61. How are endocytosis and exocytosis different? _________________________________________________________
62. What is a vesicle? ________________________________________________________________________________
63. The term “phagocyte” literally means “cell eater”. Explain why some white blood cells are called phagocytes.
__________________________________________________________________________________________________
64. What process is an amoeba using when it engulfs a food particle? ________________________________
65. What is a lysosome and what is its function? __________________________________________________________
66. What would you expect to find in exocytotic vesicles? ___________________________________________________