1. Membranes Cell membrane = Plasmalemma = Plasma membrane Surrounds cells and most organelles Forms a network of passages

2. Mitochondria, chloroplasts, and the nucleus all have a double membrane

3. Functions of plasmalemma 1.Keep cell contents together and separate from other cells 2.Controls movement of substances into and out of cells 3.Allow communication between cells 4.Attachment for intracellular cytoskeleton, cell walls and intercellular adhesions

4. Phospholipids Membranes are made of Phospholipids Hydrophilic Polar head Hydrophobic Non-polar tails

6. Hydrophobic tails Hydrophilic heads Watery cytosol

7. Water outside cell Hydrophobic tails Watery Cytoplasm

9. Fluid mosaic theory Phospholipids are not bound to each other Like oil on water Water inside and outside the cell http://www.youtube.com/watch?v=ULR79TiUj80& feature=relatedhttp://www.youtube.com/watch?v=ULR79TiUj80& feature=related (fluid mosaic model, 1.5 min)

10. Permeability selectively permeable Membranes are selectively permeable Allow some molecules through but not all

11. Permeability of membrane Some membranes impermeable (eg surfaces designed to retain water such as skin, scales, exoskeletons)

12. MENU Key Words Exercises Quick Quiz Videos Extra slides

13. Key words Phospholipids Bilayer Fatty tails Phosphate head Impermeable Permeable Large molecules Ions Fluid Mosaic Back to menu

14. (VERY) Quick quiz 1.____ are the main component of membranes 2.They consist of hydrophobic ____ 3.And a hydrophilic ____ 4.They also have integral and peripheral ____ Answers Back to menu

15. (VERY) Quick quiz 1.Phospholipids are the main component of membranes 2.They consist of hydrophobic tails 3.And a hydrophilic head 4.They also have integral and peripheral proteins Back to menu

16. Exercise Workbook pp50-52, qq18-20 and 22-23 Booklet p3 READING Pathfinder p48 (or p42) Enzymes & reaction rate Excellence in Biology pp114-6 Back to menu

17. Videos http://www.youtube.com/watch?v=E90D4Bm aVJM&feature=relatedhttp://www.youtube.com/watch?v=E90D4Bm aVJM&feature=related (10 min, includes biotechnology) http://www.teachersdomain.org/asset/tdc0 2_int_membraneweb/http://www.teachersdomain.org/asset/tdc0 2_int_membraneweb/ (interactive - membrane) Back to menu

18. Glycoproteins & glycolipids for cell recognitionhttp://www.5min.com/Video/Proteins-as-the-Mosaic-of- the-Cell-Membrane-150624158 Back to menu

19. Peripheral proteins Partially embedded  intrinsic – inside cell  extrinsic – outside cell Back to menu

20. OIL AND WATER I told you this would be important! Back to menu

21. Trans-membrane (integral) proteins involved in facilitated and active transport Back to menu