Exchange with the Environment

1. Exchange with the Environment Chapter 4 section 1

2. Warm up: cell membrane Function of a cell membrane: 1- protect the cell 2. Control the ingoing and outgoing of substances 3. Selectively permeable (semi-permeable) allow selected substances in and others are kept out

3. Structure of the cell membrane

4. Introduction • What would happen to a factory if its power were shut off or its supply of raw materials never arrived? • What would happen if the factory couldn’t get rid of its garbage?

5. Like a factory, an organism must be able to obtain energy and raw materials and get rid of wastes. • The exchange of materials between a cell and its environment takes place at the cell’s membrane. To understand how materials move into and out of the cell, you need to know about diffusion.

6. Diffusion http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html Do questions 1-5 on the activity sheet

8. Osmosis http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html Do questions 1 and 2 on the activity sheet of the osmosis part

10. Osmosis in RBC

11. Passive transport

12. Active transport

13. Difference between active and passive transport

14. Endocytosis and exocytosis

15. Closure • vesicle fuses with the cell membrane and releases the particle to the outside of the cell. • Osmosis is the diffusion of water through a semi-permeable membrane. • Cells move small particles by diffusion, which is an example of passive transport, and by active transport. • Large particles enter the cell by endocytosis, and exit the cell by exocytosis.

16. Do not forget Homework SW-Q2 3.1 “Diversity of cells” 3.2 “Eukaryotic cells” 3.3” Organization of living things” Worksheets, section and chapter review as well as quizzes done • Section review questions 1-8 of section 4.1 “ Exchange with the environment”