Starter 9/8/2014

What are some examples of osmosis and diffusion??? Decide whether the situation is isotonic, hypertonic, or hypotonic

Engage – Osmosis/Diffusion Notes

Reflect – Potato Post Lab

OBJECTIVES - Understand more about osmosis and

diffusion by taking notes- Understand the results of potato lab

DIFFUSION AND OSMOSIS

DIFFUSION1. Movement of molecules from areas of high

concentration to low concentration. (Concentration Gradient)

2. Driven by the kinetic energy of molecules.

3. Rate continues until Equilibrium is reached.

a) Hypotonic (below) solution is the one with fewer solutes.

b) Hypertonic (above) solution is the one with more solutes.

c) Isotonic (same) solutions have equal amounts of solute.

4. Solutions can be…

5. Phospholipids have 2 parts: A. polar, hydrophilic ,“water-loving,” headB. 2 nonpolar hydrophobic, “water-fearing,” tails

CELL MEMBRANES

6. CELL MEMBRANES

The proteins carryout most membrane functions

Adhesion Proteins- help one cell adhere to another or to a protein.

Communication Proteins- line up with the identical proteins in the plasma membrane of another cell. The two fuse and form a channel the directly connects the cytoplasm of both.

Receptor Proteins- are docks for hormones and other signaling molecules.

6. CELL MEMBRANES

Recognition Proteins- project above the plasma membrane and identify a cell as self or nonself.

Passive Proteins- have a channel through their interior to assist solutes or water by simply letting them diffuse through the channel (no energy required).

Active Transporters- active transporter proteins pump a solute across the membrane against a concentration gradient.

OSMOSIS7. Osmosis is the diffusion of water across a selectively permeable membrane, to a region where the water concentration is lower.

8. Water tends to diffuse from a hypotonic fluid into a hypertonic fluid.

9. Diffusion of a solute through a membrane is known as dialysis.

10. OSMOSIS

ISOTONIC solutions, same solute concentration between the cell and its environment.

• Rate of diffusion is at equilibrium with the environment.

10. OSMOSIS

HYPOTONIC solutions, the solution has fewer solutes.• Water concentration is lower inside the cell

than out, causing water to diffuse in to the cell from high to low concentration.

• Cytolysis – cells swells and bursts

“Hungry, Hungry,Hypo!”

10. OSMOSISHYPERTONIC solution , the solution has more

solutes.• Water concentration is higher inside the

cell than out, causing water to diffuse out of the cell from high to low concentration.

• Plasmolysis – cell shrinks (dehydrates)

OSMOSIS

11. Which direction will osmosis occur?

Cell95% H2O

75% H2O

Cell95% H2O

99% H2O

Cell95% H2O

95% H2O

HYPOTONIC

SOLUTIONHYPERTONIC

SOLUTION

ISOTONIC

SOLUTIONs