Lesson Plans

Biology 5th Edition ©1999

by Campbell, Reece, Mitchell

Week 4: Cell Structure and Function with a Focus on Membranes

Chapter 7: A Tour of the Cell
Chapter 8: Membrane Structure and Function

College Board Performance Objectives:

• Describe the similarities and differences between prokaryotic and eukaryotic cells.
• Describe the current model of the molecular architecture of membranes.
• Explain how variations in membrane structure account for functional differences among membranes.
• Explain the how the structural organization of membranes provide for transport and recognition.
• Explain the various mechanisms by which substances cross membranes.
• Explain how compartmentalization organizes a cell's functions.
• Relate the structures of the various subcellular organelles to their functions.
• Explain how organelles function together in cellular processes.
• Describe the factors that limit cell size.

College Board Lab Objectives:

• Relate the mechanisms of diffusion and osmosis and their importance to cells.
• Explain the effects of solute size and concentration gradients on diffusion across selectively permeable membranes.
• Explain the effects of a selectively permeable membrane on diffusion and osmosis between two solutions separated by the membrane.
• Explain the relationship between solute concentration and pressure and the water potential of a solution.
• Explain the concept of molarity and its relationship to osmotic concentration.
• Measure the water potential of a solution in a controlled experiment.
• Determine the osmotic concentration of living tissue or an unknown solution from experimental data.
• Describe the effects of water gain or loss in animal and plant cells.
• Relate osmotic potential to solute concentration and water potential.

Suggested Laboratory Experiments:

• Biology AP* Laboratory 1, Diffusion and Osmosis (Extended to the analysis of the diffusion of NaCl using conductivity sensors with Calculator-Based Laboratories or Computer-Based Laboratories.)
• Biology AP* Laboratory 1, Diffusion and Osmosis, is adapted to using the conductivity sensors with Calculator-Based Laboratories or Computer-Based Laboratories. The traditional diffusion part of the lab qualitatively analyzes the diffusion of potassium iodide. The conductivity sensors allow an extended quantitative analysis of the diffusion of NaCl. Also, the quantitative study of osmosis can be accomplished with the biology gas pressure sensors, in place of using the change of mass of dialysis tubes filled with sugar water that are soaked in pure water. The use of the biology gas pressure sensor and the conductivity sensor with the computer or CBL allows for an efficient lab that is easy to understand. The Vernier Web site has information about using sensors.

Resources:

• Chapter 7: A Tour of the Cell, pp. 102–129
• Chapter 8: Membrane Structure and Function, pp. 130–146
• Instructor's Guide, pp. 67–102
• Student Study Guide, pp. 39–57
• Test Bank, pp. 65–91
• Lab Manual: Lab Topic 3: Microscopes and Cells, pp. 57–80, and Lab Topic 4: Diffusion and Osmosis, pp. 81–110
• CD-ROM: Chapters 7 and 8 include narrated presentations, activities, and links to the Internet.

Pacing Guide:

• Chapter 7: A Tour of the Cell—1.5 days
  Use a water balloon with a marble or ball in it and a large Styrofoam ball that is covered with Parafilm and is cut in half with a large super ball inserted in the center as a nucleus as models of an animal cell. Use a shoebox lined with aluminum foil or wax paper, with a ball in the center as the nucleus, as a model of a plant cell. Describe each type of cell. Use a large serrated-edge bread knife to cut the plant cell model in half to show how a cross-section of a cell is obtained.
• Chapter 8: Membrane Structure and Function—1.5 days
  Now begin to peel back the cell membrane (Parafilm) on the animal cell model and discuss the structure and function. Focus on the 3-D of the membrane and how it would appear under the microscope. Open the shoebox and have students describe what structure the box represents and what structure the aluminum foil lining represents. Now discuss the similarities and differences of plant and animal cells and the advantages and disadvantages of each. Use a colander to help in the analysis of the semi-permeable property of cell membranes. Pour water with large marbles into the colander and then discuss the results. Repeat with sand water and discuss and relate the results to a cell membrane.
• AP* Lab 1—2 days
  This is a multipart lab that explores diffusion, osmosis in a model system, and osmosis in a living system, and students need to be well prepared to do the lab. Students need to understand the purpose and procedure of each part. Students need to work water potential problems before they do the lab.
• Block Scheduling
  Respiration can be accomplished in a little more that one and three quarter blocks and the extended activity takes about one and one quarter blocks and allows for the extended teaching of respiration.

Key Words:

Suggested Exercises:
Critical thinking questions and end-of-chapter activities are included in these exercises.

1. Challenge Questions, p. 129 #1–2 and p. 146 #1–3
2. Science, Technology, and Society, p. 129 #1–2 and p. 146 #1–2
3. Also, have students design an endomembrane system with common materials. Have them write an explanation of the structure and function of the various parts of their model.

Troubleshooting Tips/Error Traps:

• The structure and function of cells is important in every level of biology, and students must have a full understanding. Also, the structure and function of enzymes is foundational to the study of most biological principles. The investment of class interaction on these topics is critical to successfully acquiring many other concepts. It is also important that students learn how to analyze images from microscopes.
• Much attention needs to be given to the lab. Be sure to explore water potential calculations prior to the lab, and be sure that students understand the procedure. Use large drinking cups in place of lab glassware.