2. Grade breakdowns—Period 5  A=4  B=5  C=13  F=3 (Mandatory tutoring)

3. Build a cell membrane  Aka lipid bilayer  Aka plasma membrane LABEL 5 components Label outside and inside cell

4. Pick up 2 different scripts from demo table (1 per 2 people)  Practice with a partner  What is the role of: -nucleus -RNA -ribosomes -rough ER -Golgi -transport vessicles Draw diagram

5. Danish Review  Make 4 higher level questions from 1)Ecology 2)Evolution 3)Chemistry 4)Cells how does... compare/contrast with...? what evidence can you list for...? SYNTHESIS creating a unique, original product that may be in verbal form or may be a physical object combination of ideas to form a new whole what would you predict/infer from...? what ideas can you add to...? how would you create/design a new...? what might happen if you combined...? what solutions would you suggest for...? EVALUATION making value decisions about issues resolving controversies or differences of opinion development of opinions, judgements or decisions do you agree that...? what do you think about...? what is the most important...? place the following in order of priority... how would you decide about...? what criteria would you use to assess...?

6. Announcements  Cells test moved to Thursday, Dec 1  Lab report due tomorrow  Keep your Chapters 8 + 9 notes  Answer a flashcard for 0.5 points

7. Ch.7~MembraneStructure&Function Fluid mosaic model

8. Exit Quiz: Membrane 1)Draw a membrane and label 5 components 2)Describe the role of 6 of the 6 membrane proteins Bonus: Explain the 4 levels of a protein

9. Membrane structure, I  Selective permeability  Amphipathic~ hydrophobic & hydrophilic regions  1935 Davson Danielli sandwich model  Singer-Nicolson: 1972 fluid mosaic model

10. Cell membrane must be more than lipids…  In 1972, S.J. Singer & G. Nicolson proposed that membrane proteins are inserted into the phospholipid bilayer It’s like a fluid… It’s like a mosaic… It’s the Fluid Mosaic Model!

11. Membrane is a collage of proteins & other molecules embedded in the fluid matrix of the lipid bilayer Extracellular fluid Cholesterol Cytoplasm Glycolipid Transmembrane proteins Filaments of cytoskeleton Peripheral protein Glycoprotein Phospholipids 1972, S.J. Singer & G. Nicolson proposed Fluid Mosaic Model

12. Phospholipids Fatty acid Phosphate  Phosphate head l hydrophilic  Fatty acid tails l hydrophobic  Arranged as a bilayer Aaaah, one of those structure–function examples “repelled by water” “attracted to water”

13. Arranged as a Phospholipid bilayer polar hydrophilic heads nonpolar hydrophobic tails polar hydrophilic heads  Serves as a cellular barrier / border H2OH2O sugar lipids salt waste impermeable to polar molecules

14. Cell membrane defines cell  Cell membrane separates living cell from aqueous environment l thin barrier = 8nm thick  Controls traffic in & out of the cell l allows some substances to cross more easily than others hydrophobic (nonpolar) vs. hydrophilic (polar)

15. Permeability to polar molecules?  Membrane becomes semi-permeable via protein channels l specific channels allow specific material across cell membrane inside cell outside cell sugaraa H2OH2O salt NH 3

16. Cell membrane is more than lipids…  Transmembrane proteins embedded in phospholipid bilayer l create semi-permeabe channels lipid bilayer membrane protein channels in lipid bilyer membrane

17. 2007-2008 Why are proteins the perfect molecule to build structures in the cell membrane?

18. Proteins domains anchor molecule  Within membrane l nonpolar amino acids hydrophobic anchors protein into membrane  On outer surfaces of membrane in fluid l polar amino acids hydrophilic extend into extracellular fluid & into cytosol Polar areas of protein Nonpolar areas of protein

19. NH 2 H+H+ COOH Cytoplasm Retinal chromophore Nonpolar (hydrophobic)  -helices in the cell membrane H+H+ Porin monomer  -pleated sheets Bacterial outer membrane proton pump channel in photosynthetic bacteria aquaporin = water channel in bacteria function through conformational change = protein changes shape Examples H2OH2O H2OH2O H+H+ H+H+

20. Many Functions of Membrane Proteins Outside Plasma membrane Inside Transporter Cell surface receptor Enzyme activity Cell surface identity marker Attachment to the cytoskeleton Cell adhesion “Antigen” “Channel”

21. Membrane Proteins  Proteins determine membrane’s specific functions l cell membrane & organelle membranes each have unique collections of proteins  Classes of membrane proteins: l peripheral proteins loosely bound to surface of membrane ex: cell surface identity marker (antigens) l integral proteins penetrate lipid bilayer, usually across whole membrane transmembrane protein ex: transport proteins –channels, permeases (pumps)

22. Membrane carbohydrates  Play a key role in cell-cell recognition l ability of a cell to distinguish one cell from another antigens l important in organ & tissue development l basis for rejection of foreign cells by immune system