1. VII. Cell Parts Dissecting the cell

2. Quick Definitions 1. Homeostasis is the process of maintaining the cell’s environment. 2. Selective permeability is the process where a cell allows some molecules into the cell and not others.

3. A. Plasma Membrane 1. Cells must control the materials that enter and leave. 2. The PM is the boundary between the cell and it’s environment.

4. 3. PM Structure a) PM is made of a phospholipid bilayer i.Two phospholipid layers ii.Hydrophilic – “likes” water iii.Hydrophobic – “afraid” of water

5. 4. Transport across the PM a) Fluid Mosaic Model b) Transport Proteins

6. B. Cell Wall 1. Structure = Rigid layer on the outside of the cell membrane a) Think egg shell and membrane 2. Function = cell support and protection 3. Only in plants!

7. C. Cytoplasm 1. Structure = Clear, jelly-like fluid that fills the cell a)Mostly water 2. Function = Allows molecules to be transported through the cell

8. Control Centers The Nucleus, Ribosomes, and Centrioles

9. D. Nucleus 1. Structure: Two membrane layers 1.Nuclear pores allow RNA to exit nucleus a)Nucleolus i. Creates ribosomes 2. Function: 1.The nucleus contains the genetic material for the cell (called chromatin)

10. E. Ribosomes 1. Structure = very small organelles 1.small dots 2.Found a) in the cytoplasm b) on the ER 2. Function = makes proteins

11. F. Centrioles 1. Structure: Small barrel shaped organelles a) Made up of bunches of microtubules 2. Function: Involved in cell division 3. Found only in animal cells