2. Organization of Life Cell Tissue Organ Organ System Organism

3. Cells All living organisms on Earth are divided in pieces called cells. There are smaller pieces to cells that include proteins and organelles. Cells hold all of the biological equipment necessary to keep an organism alive and successful on Earth.

4. Organelles Means “little organ” Small parts of the cell Each with their own special job in the cell

5. Examples of Organelles Nucleus Rough Endoplasmic Reticulum (ER) Smooth ER Ribosomes Golgi apparatus Cell Membrane Cytoskeleton Mitochondria Lysosomes Plants Only: Chloroplast Vacuoles Cell Wall

6. Prokaryote Unicellular organism Lack membrane bound organelles No nucleus Ex: bacteria

7. Eukaryote Unicellular or Multi-cellular organism Contain a true nucleus and membrane bound organelles Ex: yeast, plants and animals

8. Nucleus The nucleus is the brain of the cell. Contains the genetic material – DNA. (Code for making proteins) Not all organisms have a nucleus. Nucleus (yellow)

9. Nucleus The nucleolus is a small section of the nucleus. (usually in the center) The nuclear membrane is a thin membrane around the nucleus.

10. Cell Membrane Also called the plasma membrane The boundary between the cell and its environment. 1 Protein

11. Cell Membrane It’s Function: Protection of the cell –Keeps bad things from coming in –Allows needed materials in –Keeps good things in –Allows wastes out This is called selective permeability – allows some molecules to pass through while keeping others out. 2

12. Cell Membrane The cell membrane allows the cell to maintain homeostasis. –Homeostasis- the ability of an organism to maintain equilibrium and survive. 3

13. Cell Membrane Structure Made of 2 phospholipids back to back. The membrane is NOT water soluble. One phospholipid Bilayer of the Membrane 4 Head Tail

14. Cell Wall Surrounds a plant cell Inflexible compared to cell membrane Provides support and protection Permeable to all molecules

15. Cell Wall Cell Membrane Inside of Cell All plant cells have BOTH a cell wall and a cell membrane

16. Jelly-like fluid that fills a cell All organelles are suspended in the cytoplasm Cytoplasm

17. Cytoskeleton Scaffolding or skeleton structure in the cytoplasm Maintains cell shape, protects the cell, & enables the cell to move

18. Endoplasmic Reticulum (ER) Interconnected tubes & vesicles Responsible for: –Protein transport –Production & storage of biomolecules Usually found near the nucleus

19. Endoplasmic Reticulum (ER) Smooth ER –Has no Ribosomes Rough ER –Has ribosomes on the surface

20. Ribosomes Location of protein production in the cell. Small structure made of RNA and protein that is NOT membrane bound (no membrane). Use the “recipe” written on DNA to make proteins. *Remember: DNA can’t leave the nucleus so RNA is the messenger.

21. Ribosomes Attached to the ER (Endoplasmic Reticulum) Can be free floating in cytoplasm Or

22. Golgi Body Function is to modify, sort and package biomolecules for use inside or outside the cell. Think of the Golgi Body as a post office.

23. Lysosomes Contain digestive enzymes They digest excess or worn out organelles, food particles and invaders (virus & bacteria)

24. Mitochondria Found in both plants and animals. Location of cellular respiration. Energy converter … converts sugars/food into energy (ATP) for the cell

25. Chloroplast Found only in plants. Location of Photosynthesis. Full of chlorophyll a green pigment.

26. Vacuole Membrane bound sac Storage for food, water & waste –Small in animals –Larger in plants

29. Multiple Cells –Stained to show the difference between the nucleus (green) and the membrane (red)

30. Red Blood Cells

31. Nerve Cell

32. White Blood Cell & Bacteria

33. Red Blood Cells flowing through blood vessels

34. Brain Cancer Cell

35. Organisms Simple Organisms: –Are unicellular –Very basic –Growth is restricted Complex Organisms: –Are multi-cellular –Can be basic or complex –Have the ability to grow Salmonella typhimurium invading human cells

36. Cells Alive! Size? –http://www.cellsalive.com/howbig.htmhttp://www.cellsalive.com/howbig.htm Cell Animation –http://www.cellsalive.com/cells/3dcell.htmhttp://www.cellsalive.com/cells/3dcell.htm

37. Resources Wikipedia Cells Alive! Biology4Kids.com