The document defines the key parts of the cell including the cell membrane, cell wall, cytoplasm, cytoskeleton, nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, mitochondria, chloroplasts, vacuoles, lysosomes, vesicles, and centrioles. It describes the basic functions of each part such as the cell membrane controlling what enters and leaves the cell, the nucleus containing DNA and directing cell activities, mitochondria converting sugar to energy, and chloroplasts facilitating photosynthesis in plant cells.

1. Definition ReviewParts of the Cell

2. *Cell Membrane* Surrounds and protects ALL cells Controls what enters and leaves cell

3. *Cell Wall* Extra support and protection Plant cells only Outside cell membrane

4. *Cytoplasm* Thick, gel-like fluid that fills the cells (what the organelles float around in)

5. *Cytoskeleton* Long strands of proteins give internal structure and shape to the cell Help cells move Eukaryotic cells only

6. *Nucleus* Directs activities of the cell Contains most of the cell’s DNA In the center is the NUCLEOLUS, which makes ribosomes Surrounding the nucleus is the nuclear membrane, which has pores that allow for certain molecules to pass through

7. *Ribosomes* Make proteins Found attached to the Endoplasmic Reticulum and floating free in the cytoplasm In all cells

8. Endoplasmic Reticulum Many different jobs Transports proteins and other substances throughout the cell Folded layers

9. Golgi Apparatus Receives proteins from the ER Sorts, packages, and sends materials throughout the cell Folded layers

10. *Mitochondria* Converts sugar into energy that the cell can use Has a double membrane Has some of its own DNA May have originally been a free-living prokaryotic organism

11. *Chloroplast* Site of photosynthesis (production of sugar using sun’s energy) Found in plant cells only Double membrane Also has its own DNA

12. *Vacuole* Stores a variety of materials Water, waste, enzymes, food particles, ions, etc Single large vacuole in plant cells, holds mostly water Several small vacuoles in animal cells

13. Lysosomes Break down and recycle old cell parts Defend against invading bacteria and viruses Contain enzymes Small Membrane-bound Found mostly in animal cells

14. Vesicle Temporary Isolate materials for transport Small Membrane-bound

15. Centriole Aid in cell division Found only in animal cells