Take out your homework

The setup below shows an osmometer. An osmometer is a device that measures osmotic pressure exerted by a liquid passing through a semipermeable membrane.

1) How can the height of the liquid in the tube increase? Isn’t that going against gravity?

Here are ‘results’ from the setup. The graph shows results from two different sucrose solutions (lines A and B).

2) If line B represents 5% sucrose, approximately how concentrated was ‘line A’?

Cell Membrane•Why have it?•What does it do?•How does it do that? Draw it!

Moving things across•Diffusion•Can enough things move across via diffusion?•Water?•Diffusion vs Facilitated Diffusion?•Draw it!•Osmosis vs Diffusion

Cell Specialization• Explain the diagram; what is the setup showing, why the change, etc

•Osmosis and diffusion – things move from high concentration to low concentration•How do things move against the

concentration gradient?•What is required to make it happen?•Draw it!

•Other examples

Think it, draw it…• If a cell is about 0.8% salt, what would

happen to the cell if it was surrounded by:•A 0.2% salt solution?•A 6.0% salt solution?•How about a PLANT cell?

Homework• Test tomorrow!!!