Question

. For each of the 3 situations below, use an arrow to indicate the net movement of water into or out of the cell through the semipermeable plasma membrane (i.e. osmosis). (Assume that the sugar molecules cannot pass through the plasma membrane in each case.)

1% sugar (inside a circule) 3% sugar (inside a circule) 1% sugar (inside a circule)

5% sugar 1% sugar   1% sugar

3. In each of the drawings above, indicate if the inside of the cell is hyperosmotic, hypoosmotic, or isoosmotic to the surrounding (outside) solution.

4. The plasma membrane is _________________permeable. This means that ____________ ______________________________________________________________________.

5. Diffusion always causes particles to move from a region of _______________ concentration to a region of ______________ concentration.

6. Does a cell expend energy when molecules diffuse in or out of the cell?

7. Consider the solution in the drawing below, with the two sides divided by a perforated membrane. In the blank drawing on the right (“After”), show how the solution would look once it has reached equilibrium, i.e. the two sides are isotonic. Assume the molecules can diffuse across the perforated membrane.

  

8. Suppose that a cell membrane is permeable to water but impermeable to glucose (sugar). The cell is in a hypotonic environment. Using the diagram below, (1) draw what the concentrations of glucose would look like at the beginning of the experiment ( use small circles to represent glucose molecules), and (2) (2) indicate the direction of movement that would occur during osmosis. Which molecule would move? ___________

Inside cell (inside a circle) Outside environment

9. Explain what happens to your cells if you drink seawater. Use the terms osmosis, hypertonic, and hypoosmotic in your description.

10. Explain what type of solution you would need to place plant cells in to increase the turgor pressure inside the plant's cells.

Answer 1