CELL STRUCTURE AND FUNCTIONS

1. CELL STRUCTURE AND FUNCTIONS

2. Cell Types Prokaryotic: has no nucleus Eukaryotic: has a nucleus and membrane bound organelles • Important: Both types have DNA

3. Common factors in all cells! • Cell Membrane • Cytoplasm • DNA (the genetic code)

4. Organelle • “little organs” • A subunit in a cell that has a special function

5. Cell Structure and Function • Plasma membrane (cell membrane) • Surrounds and protects cells • Selectively permeable • Maintains cellular homeostasis

6. Structure of the Plasma Membrane • Phospholipid Bilayer • Hydrophobic tails • Hydrophilic heads • Embedded and surface proteins • Transport • Cell cell identification • Cholesterol • Prevents fatty acid chains from sticking together

7. Plasma membrane • Phospholipid bilayer • Outermost layer and inner most layer are water-soluble • Middle layer is water-insoluble

8. Structure of the Plasma Membrane • Embedded and surface proteins • Transport • Cell to cell identification • Cholesterol • Prevents fatty acid chains from sticking together

9. Structure of the plasma membrane • Cholesterol • Prevents the layers from sticking together • Helps the cell membrane hold its form Cholesterol

10. Cytoplasm • Clear gelatinous fluid in which organelles and other cell parts are held

11. Animals vs. Plants • Both are eukaryotic plant cellanimal cell

12. How do plant and animal cells differ? • Plant cells have a cell wall and contain chloroplasts- animal cells lack these structures Cell Wall Chloroplasts

13. Cell Wall • Found in plant cells, fungi, and most bacteria • Made of cellulose

14. Cell wall Function • Provides added protection and structure • Is porous and allows any molecule that is not too big to pass (is not selectively permeable)

15. Plants maintain their basic structure because of the cell wall. Turgid Placid