1. The Cell Membrane Chapter 2 Section 2.1- The Components of Cells Topics: Structure, Function, Diseases

2. Why is the cell membrane so important? Controls what molecules enter and leave Selectively permeable O 2, CO 2, and water can pass straight through membrane Charged or larger molecules need channel or carrier proteins to enter.

3. What are the parts of a cell membrane? Phospholipids – Create a bilayer – Phosphate head Hydrophilic- loves water so exposed to watery internal & external cell environment – 2 lipid tails Hydrophobic- hate water so are found in the middle of the membrane

4. What are the parts of a cell membrane? Glycoproteins- carbohydrate chains attached to proteins embedded in CM Glycolipids- carbohydrate chains attached to phospholipids embedded in CM Both of these help other cells recognize each other

5. What are the parts of a cell membrane? Receptor Proteins – Have indentations or shapes that fit and hold molecules outside the cell. – Ligand- molecule that binds to the active site of a receptor – After ligand binds to receptor a cascade of chemical reactions occur inside cell – EX: Ligand might send a message inside the cell to tell cell to make more mucous, hormone, etc.

6. What are the parts of a cell membrane? Selective channel protein- allows certain ions into/out of cell; like a tube for passive movement of larger or charged ions Adhesion proteins- connect two bilayers to each other Enzymes- speed up chemical reactions Carrier protein- open and close to dump molecules in/out Carrier protein clip

7. What are the parts of a cell membrane? Cholesterol – gives cell membrane some structure so it is not “mushy” – Keeps cell membrane from freezing in cold weather

8. Why is the cell membrane called a fluid mosaic model? Mosaic- b/c it is studded with so many different proteins, carbohydrates, enzymes, etc. Fluid- b/c the molecules are not rigidly joined. They are moveable around each other Fluid Mosaic Video Clip

9. Cell Membrane Rap! https://www.youtube.com/watch?v=Pfu1DE9PK2w

10. What types of diseases are associated with proteins in the cell membrane? Congenital Insensitivity to Pain (CIP)- – sodium channel proteins are mutated and block sodium ions which leads to decreased or absent nerve impulses – No nerve impulses= can’t feel pain Normal Sodium Channel Video Clip

11. What types of diseases are associated with proteins in the cell membrane? Paroxysmal extreme pain disorder (PE or PEPD) – Sodium channel proteins are mutated and left open too long causing a prolonged and intense pain response

12. What types of diseases are associated with proteins in the cell membrane? Cystic Fibrosis (CF) – Abnormal sodium and chloride channel proteins – Sodium chloride trapped inside cell draws water out of mucous lining lungs/pancreas which causes mucous to be very thick. – CF patients have difficulty breathing due to thick mucous secretions in pancreas and lungs, & frequent lung infections