Diffusion and Osmosis

Biology

Ask Yourself What is moving?

If molecules move: its diffusion

Diffusion moves molecules from an area of high concentration to an area of low concentration.

NO ENERGY REQUIRED!

Diffusion Simulation http://highered.mcgraw-hill.com/sites/

0072495855/student_view0/chapter2/animation__how_diffusion_works.html

You practice Complete the Part I Of the handout on diffusion

(3 minutes)

OSMOSIS Water is moving!!!!

To the side with more solute!!!!

NO ENERGY REQUIRED!!!

Solute vs. Solvent Solute: molecule that dissolves in solution. Ex.

Sugar, salt

Solvent: Molecule that allows the solute to dissolve. Ex. Solvent

Ex. In Kool-Aid, sugar and the kool-Aid powder are the solutes. Water is the solvent.

Water is the universal solvent!

Osmotic SolutionsThere are three types of solutions into which cells may be placed:

Hypertonic Solutions

Hypotonic Solutions

Isotonic Solutions

Hypertonic Hyper= means high

Hypertonic Solutions: Higher concentration of solute

Notice: This cell has been placed into a solution with many solute molecules.

Hypertonic SolutionsWhere does water move in osmosis?

To the side with more molecules!!!!!!!!!

So where will it move?

Outside the cell!

This will cause the cell to SHRINK!!!!!

Hypertonic Solutions http://www.sascurriculumpathways.com/portal/

Launch?id=3&bhcp=1

Hypotonic HYPO means LOW

Hypotonic solutions have lower concentrations of solute compared to the inside of the cell

Hypotonic Solutions Where does the water move in Osmosis?

To the side with more solute molecules.

Water will move inside the cell and cause it to SWELL!!!!

Cells that swell up too much can burst open

http://www.sascurriculumpathways.com/portal/Launch?id=3&bhcp=1

Isotonic Solution Iso means the same

Cells that are put into isotonic solutions have the same concentrations. They are at equilibrium.

Which kind of solution Cells are placed in a beaker. The concentration of

solute (salt) molecules inside the beaker is 30%. The concentration of solute molecules inside the cell is 8% . What type of solution is this?

A.) Hypertonic

B.) Hypotonic

C.) Isotonic

A cell is placed in a solution for an hour. After the hour time period, the cell is still the same size as it was when it was first put into the solution. This cell was put into a(n)

A.) Hypertonic Solution

B.)Hypotonic Solution

C.) Isotonic Solution

A cell shrinks. It must have been placed into a(n)

A.) Hypotonic

B.) Hypertonic

C.) Isotonic Solution

Red Blood Cells