1. The Life of the Cell Chapter 3

2. Types of Movements 1. Diffusion and passive transport 2. Active Transport 3. Phagocytosis & Exocytosis 4. Osmosis

3. 1. solution

4. Passive Transport Nucleus [Low] [High] Note: Solutes move

5. 2. Active Transport: may be ions (e.g. Na+, K+ or other molecules like glucose). Requires Energy Requires a Transporter

6. Exocytosis Endocytosis and Phagocytosis 3. Movement of large molecules: requires energy also http://www.macroevolution.net/images/exocytosis-stanford-sea-urchin.gif

7. 4. Osmosis is : the movement of WATER from a region of HIGHER WATER concentration to region of LOWER WATER concentration across a semi-permeable membrane.

8. Now: A real life example of how osmosis is important to the human red blood cells. It is helpful to understand the term of “osmolarity”.

9. Osmolarity (FYI) Osmolarity is the measure of solute concentration, defined as the number of osmoles(Osm) of solute per liter(L) of solution (osmol/L or Osm/L). 1 mol/L NaCl corresponds to an osmolarity of 2 osmol/L each mole of NaCl becomes two osmoles in solution, one mole of Na+ and one mole of Cl-. Similarly, a solution of 1 mol/L CaCl2, gives a solution of 3 osmol/L (Ca2+ and 2 Cl-).

10. What happens to the shapes of the RBC? Crenation SwellingNo change 600 mOsm300 mOsm200 mOsm

11. 100 200 300 400 500 milliosmosmoles Red Blood Cells and the affect of Tonicity

12. We will next discuss our digestive system