Biology 12

Name: Cell Structure and Function Practice Exam

Cell parts and Function 1. Identify each part of the cell indicated and give one role for each structure in the secretion and/or synthesis of a protein. (6 marks) NOTE: A points to the nucleolus

Structure A

B

C

D

E

F

Function in protein synthesis and/or secretion

2. Explain why a cell membrane is described as selectively permeable. (1 mark)

3. State one function of the following: (6 marks) a) mitochondria

b) lysosomes

c) rough endoplasmic reticulum

d) Golgi apparatus

e) ribosomes

f) smooth endoplasmic reticulum

4. Draw and label the parts of the fluid mosaic model of a cell membrane. Describe the role of each of these components. (6 marks) • Phospholipid bilayer • Carrier protein • Embedded protein • Cholesterol • Glycolipid • Glycoprotein

Use the following diagram to answer questions 5-7 5. Molecule W functions to a) provide cell movement b) transport ions into the cell c) package cell products for export d) provide a selectively permeable membrane

6. Which molecule allows glucose to enter and exit the cell? a) W b) X c) Y d) Z 7. The structure labeled X is called a) lipoprotein b) glycolipid c) glycoprotein d) phospholipids 8. Glycolipids and glycoproteins can function as? a) Passageways into the cell b) Antigens and receptor sites c) Structural components of the cell membrane d) Help keep the cell membrane flexible 9. When insulin attaches to a glycoprotein it a) Opens the carrier protein for glucose to enter the cell b) Closes the carrier protein to prevent glucose from entering the cell c) Marks the cell for phagocytosis d) Causes the cell to take in glucose by pinocytosis 10. Explain why the following phrases are true: (1 mark each) a) Cells that secrete proteins have many Golgi bodies.

b) Larger organisms are made of more cells, NOT bigger cells.

Osmosis and Diffusion (Passive Transport) 11. A 0.9% NaCl solution is isotonic to red blood cells. Which statement describes the results if red blood cells are placed in a 9% solution of NaCl? a) they will burst b) they will shrink c) nothing will happen d) they will expand but not burst 12. Which term below refers to the bursting of an animal cell? a) plasmolysis b) crenation c) lysis d) turgor pressure 13. An animal cell will always take in water when placed in a a) hypertonic solution b) osmotic solution c) isotonic solution d) hypotonic solution 14. Uptake of solutes by a cell from an isotonic medium will be followed by osmosis. a) true b) false 15. Describe how the structure of the cell membrane permits molecules to enter the cell by the following processes. (1 mark each) a) Osmosis:

b) Facilitated Transport (Facilitated diffusion):

16. Describe two ways to increase the rate of diffusion across the membrane (2 marks)

17. Use the following experimental setup to answer question 16.

a. Describe what happens to the concentration of glucose solution on side B. Explain (2 marks)

b. Describe what happens to the concentration of copper sulphate solution on side A. Explain. (2 marks)

18. An experiment was designed to measure the effect of tonicity on potato cells. Six potato sections, all identical in size and mass and cut from the same potato, were placed in varying concentrations of sucrose and distilled water solutions. The mass of the sections was taken before the experiment and 24 hours after the experiment began. The percentage change in the mass of the cells was recorded as follows. Section 1 2 3 4 5 6

Sucrose concentration in mol/L 1.0 0.8 0.6 0.4 0.2 0.0

Change in the Mass due to water loss or gain (expressed as a percent) -20 -15 -12 +2 +5 +8

a. Explain why some potato sections lost mass and why some gained mass. (2 marks)

b. Approximate a sucrose concentration that would be isotonic to the potato cell. (1 mark)

c. Why was distilled water used as the solvent for this experiment? (1)

19. Plant tissue was placed in a starch solution. The following data were gathered over an 80 minute period.

a. Plot the data on the graph provided. (1 mark)

b. Explain the process occurring in the plant tissue between 0 and 60 minutes. (2 marks)

c. Name the substance that was added to the solution at 60 minutes and explain how this substance caused the change illustrated on the graph. (2 marks)

Active vs. Passive Transport 20. A small lipid soluble molecule passes easily through the cell membrane. Which of these is most likely the explanation? a) a protein carrier must be at work b) cell membrane is composed of lipids c) the cell is expending energy for this d) phagocytosis has enclosed the molecule 21. Which of these does not require an expenditure of energy? a) diffusion b) osmosis c) facilitated transport d) all of these 22. The thyroid gland contains a high concentration of iodine. This is an example of a) passive transport b) active transport c) facilitated transport d) endocytosis 23. Cell drinking is synonymous with a) cell eating b) endocytosis c) phagocytosis d) pinocytosis 24. Which of the following is actively transported across cell membranes? a) carbon dioxide (CO2) b) oxygen (O2) c) water (H2O) d) sodium (Na+) 25. Describe the differences between active and passive transport. (4 marks) Passive Transport Active Transport Place the following in the correct box: osmosis, diffusion, phagocytosis, pinocytosis, carrier protein pumps, carrier protein pores Describe 2 differences between passive and active transport

26. Describe the differences between the following types of active transport. (3 marks) Type of active transport Description Carrier protein pumps

Pinocytosis

Phagocytosis

Exocytosis (secretion)

27. Describe the role of lysosomes in a white cell after bacteria are engulfed by phagocytosis. (How would these bacteria be destroyed?) (2 marks)