1. Cell Organelles © J Beauchemin 2006

2. Cell Organelles Organelle= “little organ” Found only inside eukaryotic cells Everything in a cell except the nucleus is cytoplasm

3. Cell Membrane Boundary of the cell: helps control what enters and leaves cell Made of a phospholipid bilayer

4. 4 The Cell Membrane is Fluid Molecules in cell membranes are constantly moving and changing copyright cmassengale

5. 5 Jelly-like substance enclosed by cell membrane Provides an area for chemical reactions to take place Cytoplasm of a Cell cytoplasm copyright cmassengale

6. 6 Contains organelles to carry out specific jobs Found in ALL cells More on Cytoplasm cytoplasm copyright cmassengale

7. Nucleus Control center of the cell Contains DNA Surrounded by a double membrane Usually the easiest organelle to see under a microscope Usually one per cell

8. 8 Nucleolus Inside nucleusInside nucleus Cell may have 1 to 3 nucleoliCell may have 1 to 3 nucleoli Disappears when cell dividesDisappears when cell divides Makes ribosomes that make proteinsMakes ribosomes that make proteins copyright cmassengale

9. Cytoskeleton Acts as skeleton and muscle Provides shape and structure Helps move organelles around the cell

10. Cytoskeleton: 2 kinds Microfilaments are threadlike & made of ACTIN Microtubules are tubelike & made of TUBULIN MICROTUBULES MICROFILAMENTS

11. Centriole Aids in cell division Usually found only in animal cells Made of microtubules

12. Endoplasmic Reticulum A.k.a. “ER” Connects to nuclear envelope & cell membrane Highway of the cell 2 kinds Rough Rough Smooth Smooth

13. 13 Rough Endoplasmic Reticulum (Rough ER) Has ribosomes on its surfaceHas ribosomes on its surface Makes membrane proteinsMakes membrane proteins Helps EXPORT proteins out of cell.Helps EXPORT proteins out of cell. Connected to the nucleusConnected to the nucleus copyright cmassengale

14. 14 Smooth Endoplasmic Reticulum Smooth ER lacks ribosomes on its surface Is attached to the ends of rough ER Makes cell products that are USED INSIDE the cell copyright cmassengale Makes membrane lipids (steroids) Regulates calcium (muscle cells) Destroys toxic substances (Liver)

15. Ribosome Site of protein synthesis Found attached to rough ER or floating free in cytoplasm Produced in a part of the nucleus called the nucleolus That looks familiar…what is a polypeptide?

16. Golgi Apparatus Looks like a stack of plates Stores, modifies and packages proteins Molecules transported to and from the Golgi by means of vesicles

17. 17 Golgi Animation Materials are transported from Rough ER to Golgi to the cell membrane by VESICLES copyright cmassengale

18. 18 Lysosome Digestion copyright cmassengale Garbage disposal of the cell Cells take in food: phagocytosis Contain digestive enzymes that break down wastes

19. Mitochondria “Powerhouse of the cell” Bound by a double membrane Has its own strand of DNA Generate cellular energy (ATP) More active cells like muscle cells have MORE mitochondria Both plants & animal cells have mitochondria

20. Chloroplast Found only in plant cells Contains the green pigment chlorophyll Site of food (glucose) production Bound by a double membrane

21. Cell Wall Found in plant and bacterial cells Rigid protective barrier Located outside of the cell membrane Made of cellulose (fiber)

22. Vacuoles Large central vacuole usually in plant cells Many smaller vacuoles in animal cells Storage container for water, food, enzymes, wastes, pigments, etc. In plants, they store Cell Sap What type of microscope may have been used to take this picture?

23. Quick Review Which organelle is the control center of the cell? Nucleus Which organelle holds the cell together? Cell membrane Which organelles are not found in animal cells? Cell wall, central vacuole, chloroplasts Which organelle helps plant cells make food? Chloroplasts What does E.R. stand for? Endoplasmic reticulum