1. Cell Theory & Cell Organelles
Sections 3.1 & 3.2

2. 3.1 Cell Theory
Key Concept:
Cells are the basic unit of life.

3. The cell theory grew out of the work of many scientists and improvements in the microscope.
Many scientists contributed to the cell theory.
More was learned about cells as microscopes improved.

4. Early studies led to the development of the cell theory.
All organisms are made of cells.
All cells come from other cells.
The cell is the basic unit of structure & function in living things.

5. All cells share certain characteristics.
Cells tend to be microscopic.
All cells are enclosed by a plasma membrane.
All cells are filled with cytoplasm.
All cells have ribosomes.

6. There are two cell types: eukaryotic cells & prokaryotic cells
Have a nucleus
Have membrane-bound organelles
Prokaryotic cells
Do not have a nucleus (still have DNA)
Do not have membrane-bound organelles

7. 3.2 Cell Organelles Key Concept:
Eukaryotic cells share many similarities.

8. Review from 3.1
All cells have:
Plasma Membrane
Cytoplasm
Ribosomes

9. Plasma Membrane (aka Cell Membrane)
Function: Controls what enters and leaves the cell
Made of:
Phospholipids
Proteins
Carbohydrates
Cholesterol
Steroids 1 1 1
IN ALL
CELLS

10. Cytoplasm
Function: holds organelles in place; location of various reactions in the cell
Organelles: parts of the cell with specific jobs/functions 2 2 2
IN ALL
CELLS

11. Ribosomes Function: protein synthesis
Found in cytoplasm or on the Rough ER
IN ALL
CELLS

12. Nucleus Function: Control center of the cell (“brain”)
Has its own membrane
Stores DNA 4 3 4 3

13. Nucleolus Function: Makes RNA (a nucleic acid)
Found inside the nucleus

14. Endoplasmic Reticulum (ER)
 “Roadway” of the cell
Rough ER
Smooth ER
Helps make and transport proteins
Ribosomes on surface make it look rough
Helps break down toxins, poisons, and waste
Helps process carbs & lipids

15. Golgi Apparatus (Golgi body)
Function: Packages products (ex. – proteins) for the cell to export
UPS for the cell

16. Lysosomes Function: Contain enzymes to digest materials for the cell
Not found in plant cells

17. Mitochondria Function: Where energy is made for the cell
Have a double membrane
Inner membrane (cristae) is folded – this increases surface area to allow more energy to be made at a time
Other structures in the body are like this as well (small intestine, lungs)
Singular: mitochondrion

18. Plastids Chloroplast Chromoplast Site of photosynthesis (makes food)
 Pigment-containing organelles
Chloroplast
Chromoplast
Site of photosynthesis (makes food)
Make and store pigments in fruits, roots, etc. (red color in tomatoes) 6

19. Vacuole Function: Stores water and food
Plant cells: large and singular
Animal cells: small and numerous

20. Cytoskeleton
Function: helps cell maintain shape; helps cell move; helps move organelles around inside the cell (like railroad tracks)

21. Centrioles Function: helps with cell division Only in animal cells
PART OF CYTOSKELETON

22. Cilia & Flagella Function: Help with cell movement
PART OF CYTOSKELETON

23. Cell Wall Function: protection for plant, fungal, and bacterial cells5 5

24. Review Eukaryotes Prokaryotes Have nucleus (DNA)
Have membrane-bound organelles
Larger size because of organelles
More complex
Unicellular or multicellular
No nucleus (still have DNA)
No membrane-bound organelles
Smaller size because of lack of organelles
Less complex
Unicellular