1. Warm-Up Turn in Microscope Lab and vocabulary. 1. Have a clean sheet of notebook paper for the warm-up. https://www.youtube.com/watch?v=6fhbbFd4icY 1.Define the word homeostasis in your own words. 2. Based on how you defined the word homeostasis, why is the cell membrane so important for maintaining homeostasis? 3.You went out running on a hot day. After you run, you sit down and feel very warm. How will your body respond in order to maintain homeostasis? 4.You are outside on a very cold day. You feel very cold. How will your body respond in order to maintain homeostasis?

2. Important for homeostasis - the process of maintaining a constant internal environment; cell membranes are crucial to homeostasis Cell membrane = plasma membrane

3. Cell Membranes Functions: 1. Regulates what enters and leaves the cell = SEMI- PERMEABLE 2. Separates the inside of the cell from the outside 3. Recognizes/responds to outside signals

4. Membrane: Prokaryotic Cell

5. Membrane: Eukaryotic Cell

6. Cell Wall Location: Layer outside of the cell membrane in some organisms Function: Provide structure and support

7. Plants Cell Wall

8. Bacteria Cell Wall

9. Fungus

11. Phospholipid: Structure Phosphate Head Two Fatty Acid Tails Hydrophilic: LOVES water Hydrophobic: HATES water

12. Phospholipid bilayer Membrane is made up of two layers of phospholipids. With this arrangement in mind, where is the “water” in the diagram? WATER Hydrophilic Hydrophobic

13. Location: Surrounds the cell and organelles

14. Function of Phospholipids Controls what comes in and out of cells; the gatekeeper

15. Cholesterol Location: Found in between the phospholipids in the bilayer. Function: Helps keep the phospholipid bilayer from sticking together; contributing to the fluidity of the membrane

16. Proteins

17. 1. Transport or Integral Proteins A protein that spans the entire membrane helps transport larger molecules across the membrane

18. 2. Peripheral Proteins A protein that spans the surface of the membrane helps in signaling other cells

19. Carbohydrate Location: 1)On top of peripheral proteins = glycoprotein 2)Or directly on membrane = glycolipids Function: Help recognized similar cells to form tissues OR to recognize foreign substances in the cell

20. *

21. Make your own cell membrane. 1.Make you sure you have these parts labeled: phospholipid bilayer, a single phospholipid boxed, transport protein, cholesterol, carbohydrate, a nucleus, label the inside and outside of the cell. 2.On the inside write the function of these words: cell membrane, homeostasis, carbohydrate chain, transport protein, and cholesterol.