THE CELL IN ACTION!

1. THE CELL IN ACTION!

2. Factors Affecting Diffusion & Osmosis - In groups of 3, half the class will conduct factors affecting diffusion lab while the others are working on osmosis

3. Passive Transport The net movement of a substance across a membrane from an area of high concentration to an area of low concentration. NO ENERGY REQUIRED!! There is simple diffusion that allows molecules to directly diffuse through the membrane (eg. O2 & CO2) There is facilitated diffusion that uses proteins to assist with allowing molecules to cross the membrane (eg. Glucose)

4. DIFFUSION An example of Passive Transport is: Diffusion is the movement of molecules from areas of high concentration to areas of low concentration.

5. Diffusion in the Human Body Write your prediction about what happens to oxygen as it diffuses through the body. Erase within the red circles for a hint. Prediction: Lungs Cell Capillary

6. Effects of Osmosis Cell membranes are completely permeable to water, therefore, the environment the cell is exposed to can have a dramatic effect on the cell. Let's use a real life example. IV drips! (Infusion of liquid substances directly into a vein) 5% glucose, 0.9% salt - this is normal blood Solutes SUCK . . . water in or out of cell

7. Effects of Osmosis ISOTONIC SOLUTION - are solutions that have equal solute concentrations, equilibrium has been reached. When a cell is placed in this type of solution, the water diffuses _________________________. SOLUTE : SOLVENT I SO Perfect??

8. Effects of Osmosis HYPERTONIC SOLUTION - is one with a low amount of water outside the cell. Therefore there is a higher concentration of water in the cell than outside it. When a cell is placed in this type of solution, the water diffuses __________________________, causing the cell to ________________________. This could lead to a condition called CRENATION! HYPER skinny??

9. Effects of Osmosis HYPOTONIC SOLUTION - is one with a high amount of water outside the cell. When a cell is placed in this type of solution, the water diffuses ______________________, causing the cell to ________________________. This could lead to a condition called Hemolysis! HYPO - Hippo???

11. Problem Mrs. Nurse prepared three solutions of salt water (1%, 5%, 9%) and poured them into test-tubes marked A, B, C. She forgot to identify which concentration was in which test-tube. However, the students decided they could identify the solution by adding some blood cells to the test-tubes. The students knew that blood cells have an internal salt concentration of about 5%. They also knew that blood cells are impermeable to salt. They added some blood to each test-tube. Later they removed one drop of blood from each test-tube and examined the blood cells under a microscope. The blood cells in tube A were greatly swollen, and many membrane had ruptures open. The blood cells in tube B were shriveled up like raisins. The blood cells in tube C had not changed. Determine the percent concentration of the salt in tube A, B, and C and explain your answer.

12. ACTIVE TRANSPORT - the movement of substances across the cell membrane from an area of low to an area of high. Cell energy (ATP) is used to move particles through membrane. Types of Active Transport 1) Carrier Proteins - using ATP to change their shape allowing particles to be moved against the gradient You Tube Video What are the main differences between passive and active transport?

13. MOVEMENT OF LARGE PARTICLES 2) Endocytosis - cell membrane folds around a substance bringing it into the cell. There are two types: a) PHAGOCYTOSIS - when the substance engulfs a large particle ex. white blood cell 'eating' bacteria b) PINOCYTOSIS - when the substance engulfed is a liquid ex. fluids in solution

14. MOVEMENT OF LARGE PARTICLES 3) Exocytosis, the movement of unwanted materials out of the cell by pushing a vesicle to the cell surface.

16. Activity 1) Passive & Active Transport Questions - Homework 2) Osmosis Lab - Potatoes FRIDAY