Worksheet Chapter 3: Movement of Substances Across the Plasma Membrane

1. State two differences between simple diffusion and facilitated diffusion.

2. Fill in the blank: The structural model currently accepted to describe the dynamic arrangement of lipids and proteins in plasma membranes is the ________ Model.

3. True or False: Active transport can occur in dead plant or animal tissues.

4. Explain how high concentrations of salt preserve cucumber pickles from microbial decay.

5. True or False: Lipid-soluble molecules like fat-soluble vitamins (A, D, E, K) pass through the plasma membrane via carrier-mediated active transport.

6. A student places red blood cells into three test tubes containing Solution X, Solution Y, and Solution Z. - In Solution X, the cells shrink and crenate. - In Solution Y, the cells remain normal biconcave discs. - In Solution Z, the cells burst. Identify the osmotic nature of Solutions X, Y, and Z relative to red blood cell cytoplasm.

7. An experiment was conducted using Osmosis Tubing (Visking tubing) filled with a 20% sucrose solution and immersed in a beaker of distilled water. (a) Describe and explain the change in liquid level inside the Visking tubing after 1 hour. (b) Explain why sucrose molecules do not leak out into the beaker water.

8. Define the term 'plasmolysis' in plant cells.

9. Compare and contrast passive transport and active transport across the plasma membrane.

10. Which solution type causes red blood cells to swell and undergo hemolysis?