1. Passive Transport pp

2. How does the cell membrane maintain homeostasis in a cell?

4. The cell membrane has many different macromolecules embedded within the phospholipids
- Carbohydrates and lipids can be use for cell-to- cell communication or as cell markers
- Peripheral proteins are attached to the surface of the cell membrane
- Integral proteins are embedded in the bilayer and are often channel proteins.
- Cholesterol makes the membrane more fluid and less rigid at colder temperatures

5. What characteristic does the cell membrane have?
Cell membrane is nonpolar and tightly packed
Small and nonpolar substances can easily pass through the cell membrane

6. Movement across the cell membrane without energy
Passive transport:
Movement across the cell membrane without energy

7. Diffusion: movement of molecules from area of high concentration (CONC) to area of low concentration

8. Osmosis: special diffusion of water (polar) across membrane

9. A solution is made of a solute dissolved in a solvent (like water).
Water movement depends on the number of solutes outside the cell
Water moves towards the greatest number of solutes or towards the highest concentration

10. Hypertonic: CONC of solutes is higher outside the cell and water moves out the cell- cell shrinks

11. Hypotonic: CONC of solutes is lower outside the cell and water moves into the cell cell swells

12. Isotonic: CONC of solutes inside = outside; so no net water movement

14. Facilitated Diffusion

15. Polar molecules or molecules too big to move across the membrane use carrier proteins EX. Glucose and Polar molecules Similar to enzymes in that the carrier protein is specific as to what it moves