1. Movements Through Cell Membranes
BY: Mohamad Hamka, Mohamad Saleh, Ammar Alzabah, Amer Hussein

2. Pay attention and do the following….
Write at least two bullet points of what you learned today
Write at least one question you have
Also give one example of one of the passive mechanisms

3. Cell Membrane
The cell membrane is a selective barrier that controls which substances enter and leave the cell.
These movements include passive and active mechanisms.

4. Passive Mechanisms
Passive Mechanisms include (Diffusion,Facilitated Diffusion,Osmosis, and Filtration).
They do not require cellular energy.

5. Diffusion
Diffusion is the movement of molecules from areas where they're highly concentrated to less-concentrated areas.
Difference in concentration= concentration gradient
Many organs, such as the lungs and small intestine, use diffusion to keep us alive and healthy.
Example- Exchange of oxygen and carbon dioxide in the lungs.
Eventually after diffusion the molecules are uniformly distributed and their concentrations stop changing = EQUILIBRIUM

7. Facilitated Diffusion
Carrier molecules that help substances get across the lipid bilayer that are not able to pass through
Moves the substances from high concentration to lower concentration
Example- Glucose is too large to pass through membrane channels so the carrier molecules help them get across.

9. Osmosis
A special type of diffusion that occurs when water molecules diffuse to a region of higher concentration to a region of lower concentration across a selectively permeable membrane
A selectively permeable membrane allows certain molecules or ions to pass through it.
Example- When a cell shrivels or swells depending on the direction of the water.

11. Isotonic Hypertonic & Hypotonic
Isotonic- Any solution that has the same osmotic pressure as body fluids.
Hypertonic-Solutions with a higher osmotic pressure than body fluids.
Hypotonic- Solutions with a lower osmotic pressure than body fluids

13. Filtration
Molecules are not moving randomly but are forced to the other side
A process that forces molecules through membranes.
The formation of tissue fluid by forcing water and dissolved substances out of the blood capillaries.

17. Quiz Questions
(True or False) Osmosis is the process where membrane proteins help substances get across the lipid bilayer.
WHAt is the difference between isotonic, hypertonic, and hypotonic?
Do passive mechanisms require cellular energy?
In filtration molecules are being_____to the other side.