1. The Cell Membrane

2. What is the cell membrane? AKA: Plasma membrane The boundary between the cell and the environment Does every cell have a cell membrane? – Yes, Each and every cell has a cell membrane.

3. Cell membranes help maintain homeostasis, what is that? 1.Cells breathing 2.Cells getting blood to them 3.Cells maintaining internal conditions 4.Cells reproducing

4. How do cell membranes help to maintain homeostasis? The cell membrane allows nutrients to come into the cell Glucose, amino acids, lipids The cell membrane removes waste

5. Selective Permeability The cell membrane lets some molecules in and keeps others out EX. A cell is low on glucose so the membrane lets in some glucose, but does not overfill the cell with the macromolecule.

6. Structure of the cell membrane What does the cell membrane look like up close? Lets look at one of these structures up close

7. Structure of cell membrane Phospholipids – Phosphate head – Glycerol – 2 Fatty acid tails

8. When something is hydrophilic, it… 1.Has a chemical makeup that likes to be around water 2.Has a chemical makeup that does not like to be around water

9. Phospholipids 1.) Phosphate Head Polar Hydrophilic Make up the outer borders of the membrane 2.) Fatty Acid Tails Nonpolar Hydrophobic Make up the inner part of the membrane

10. Structure of cell membrane Phospholipid bilayer – 2 layers of phospholipids make up a cell membrane

11. Where would you expect to find water in this cell membrane? 1.Here 2.Here

12. Phospholipid Bilayer Remember polar heads and nonpolar tails

13. The fluid Mosaic Model of the cell membrane Lipid bilayer is not strong & firm like a hard shell, but it is fluid like a soap bubble consistency So, it is called the Fluid Mosaic Model (fluid like, with many proteins stuck in it)

14. The fluid Mosaic Model of the cell membrane It is a flexible membrane, made fluid because of cholesterol molecules located in the phospholipid bilayer. Proteins in the membrane move around.

15. Other components of the cell membrane Cholesterol – Helps to stabilize the phospholipids and keep them from sticking together

16. Other components of the cell membrane Carbohydrates- linked to lipids or proteins – Recognition of Cells – “Name tag of cell” – Ex. Is the cell a heart cell, liver cell, or brain cell? – Ex. Glycolipids & Glycoproteins (marker protein)

17. Other components of the cell membrane Proteins- make up 50 %- 70% of membrane – Regulate which molecules enter and which molecules leave a cell. – Receive info & ID the cell

18. Types of proteins in the cell membrane Carrier Protein – Allow needed substances or waste materials to move through the cell membrane

19. Types of proteins in the cell membrane Receptor Protein – These have binding sites for molecules such as hormones or substrates to bind to

20. Types of proteins in the cell membrane Channel or Pore protein – Hydrophilic channel – allows lipid insoluble substances to pass in and out of cell.

21. Types of proteins in the cell membrane Glycoproteins – Protein with what macromolecule attached to it? Carbohydrate – Functions for cell to cell recognition

22. Where are proteins located in the cell membrane? Integral Proteins – Proteins inside the cell membrane Peripheral Proteins – Proteins outside the cell membrane

23. Lets build a cell membrane together http://www.wisc- online.com/objects/index_tj.asp?objid=AP110 1 http://www.wisc- online.com/objects/index_tj.asp?objid=AP110 1 Cell membrane animation

24. This picture shows what type of protein? 1234567891011121314151617181920 21222324252627282930 1.Receptor Protein 2.Channel Protein 3.Glycoprotein 4.Carrier Protein

25. Identify the structure marked on the cell membrane: 1234567891011121314151617181920 21222324252627282930 1.Phospholipid 2.Cholesterol 3.Receptor protein 4.Channel protein 5.Glycoprotein 6.Carrier protein 7.Nucleic acid

26. Identify the structure marked on the cell membrane: 1234567891011121314151617181920 21222324252627282930 1.Phospholipid 2.Cholesterol 3.Receptor protein 4.Channel protein 5.Glycoprotein 6.Carrier protein 7.Nucleic acid

27. Identify the structure marked on the cell membrane: 1234567891011121314151617181920 21222324252627282930 1.Phospholipid 2.Cholesterol 3.Receptor protein 4.Channel protein 5.Glycoprotein 6.Carrier protein 7.Nucleic acid

28. Identify the structure marked on the cell membrane: 1234567891011121314151617181920 21222324252627282930 1.Peripheral Protein 2.Integral Protein