1. 1 The Plasma Membrane ch 8 Gateway to the Cell

2. 2 Functions of Membrane p32 Warm Up: What kind of cell is pictured to the right? How do you know? Protective Protective barrier Regulates objects in & out Allow Allow cell recognition Contains Contains the cytoplasm Allows Allows unicellular organisms to move

3. 3 Structure of the Cell Membrane-video video

4. 4 Phospholipids Cholesterol Proteins Carbohydrates (glycocalyx) Membrane Components p31 Draw and label diagram on top of left page

5. 5 Phospholipids p32 Make up the cell membrane Contains a polar head (attracts water) and non-polar tail (repels water)

6. 6 Cell Membrane p32 phospholipid bilayer. The tails face each other. made of 2 layers of phospholipids called the lipid bilayer. The tails face each other. fluid mosaic model because the phospholipids move like water in a pond fluid mosaic model because the phospholipids move like water in a pond Draw pictures on bottom of left page (31) Outside cell (water) Inside cell (water) Polar head Non polar tails

7. 7 Warm up: what’s the difference between polar and nonpolar? Small & nonpolar molecules can move through (passive=no energy). Large polar molecules & proteins do not move through the membrane on their own (active=energy needed) too big. Types of Transport Across Cell Membranes p34 Transport

8. 8 Passive Transport: 1)Simple Diffusion Simple DiffusionSimple Diffusion NORequires NO energy HIGH to LOWSmall molecules move from area of HIGH to LOW concentration naturally

9. 9 Diffusion of Liquids

10. 10 Diffusion through a Membrane draw top p33 Cell membrane

11. 11 2)Osmosis p34 Diffusion of WATER across a membraneDiffusion of WATER across a membrane Water moves from low concentration of molecules to high (draw in middle of p33)Water moves from low concentration of molecules to high (draw in middle of p33) Hypotonic Hypertonic Isotonic

12. Questions bottom p33 What’s the difference between diffusion and osmosis? Why are they called passive transport? 12

13. 13 Passive TransportPassive Transport: Passive Transport Active Transport p38 Warm up: What is a hypotonic solution? Hypertonic? Isotonic? 3)Facilitated diffusion  Uses protein channels to move particles from high to low concentration  Doesn’t require energy Use protein with gradient no energy

14. 14 Active TransportActive Transport p38 Active Transport AGAINST natural flow from LOW to HIGH concentration  Uses Transport Proteins  Requires energy Use protein Against gradient Use energy

15. 15 Warm up: what do endo, exo, and cyto mean? Endocytosis – Used to engulf large particles such as food, bacteria, etc. particles such as food, bacteria, etc. into vesicles into vesicles Called “Cell Eating” Endocytosis & Exocytosis p40

16. 16 EndocytosisEndocytosis About to Occur Endocytosis

17. 17 ExocytosisMolecules are moved out of the cell by vesicles that fuse with the plasma membrane. Exocytosis- Molecules are moved out of the cell by vesicles that fuse with the plasma membrane.

18. 18 Exocytosis Exocytic vesicle immediately after fusion with plasma membrane.

19. 19 Cell Reproduction: Mitosis

20. 20 The Cell Cycle p42 Warm up: why do cells divide? p201 The life cycle of the cell is divided into 2 phases: Interphase Mitosis Video 0:41

21. 21 Cell Cycle- draw on top left p41 Cell growth DNA Doubles Chromosomes shorten Cell Division Centrioles double

22. 22 Interphase p42 During Interphase are 3 smaller phases: G1: The cell has just divided, the DNA are uncolied and scattered, and the cell grows. S Stage: DNA replicates (doubles) and forms a chromosome with 2 sister copies G2: Chromosomes shorten and cell prepared for mitosis Draw chromosome structure top right of 39 from book p 205 fig 8.10 video

23. 23 Mitosis p42 When Interphase is complete, Mitosis occurs and the cell divides into 2 identical copies. Video 7:20

24. 24 Phases of Mitosis p42 Prophase: nucleus disappears, and centrioles move to poles of cellProphase Metaphase: chromosomes line up in the middle of cellMetaphase Anaphase: sister chromatids split apartAnaphase Telophase: the cell splits in 2, dna uncoils and nucleus reforms (Cytokinesis)Telophase

25. 25 Four Mitotic Stages 1.Prophase 2.Metaphase 3.Anaphase 4.Telophase P 207 in book, draw and label figure 8.13 on bottom of p41