1. CELL STRUCTURES and ORGANELLES

3. Nucleus Identified by Robert Brown, a Scottish botanist in 1831.
The nucleus controls most of a cell’s processes.
Contains the cell’s genetic material, DNA
Nearly all eukaryotic cell types contain a nucleus.

4. Chromatin & Chromosomes
Chromatin is a granular material visible within the nucleus
It consists of DNA bound to proteins.
During cell division chromatin condenses to form chromosomes.
Chromosomes are distinct threadlike structures containing genetic information that is passed form one generation of cells to the next.

5. Nucleolus Small, dense region within the nucleus.
Assembly of ribosomes begins in the nucleolus.

6. Nuclear Envelope
Covered with pores which allow material to move in & out, especially a steady stream of RNA to the rest of the cell.

7. Cytoskeleton
A network of protein filaments & tubules that helps a cell maintain its shape.
Also involved in many forms of cell movement.

8. Organelles in the Cytoplasm

9. Ribosomes Small particles of RNA & protein,
Assembles proteins according to coded instructions from the nucleus.
May be attached to the endoplasmic reticulum or free- floating in the cytoplasm.

10. Endoplasmic Reticulum
Internal membrane system where components of the cell membrane are assembled.
Modifies some types of proteins.

11. Endoplasmic Reticulum
Two types of ER
Rough ER
Studded w/ ribosomes
Smooth ER
Ribosome free
Involved in the synthesis and movement of lipids

13. Golgi Apparatus
Modifies proteins by attaching carbohydrates and lipids.

15. Lysosomes Filled with enzymes.
Breaks down carbohydrates, lipids, and proteins.
Breaks down organelles that have outlived their usefulness.

17. Vacuoles
Sac-like structures that store H2O, salts, carbohydrates, proteins.
In plants, large vacuoles filled with H2O makes it possible to support heavy leaves, flowers, stems.

18. Centrioles Found only in animal-type cells.
Microtubule structure that helps separate chromosomes during cell division.

20. Chloroplasts Found in plants & algae. Contain chlorophyll.
Use energy from sunlight to make energy-rich food molecules by the process of photosynthesis.

22. Mitochondria Double-membrane organelle.
Release energy from stored food molecules.
Energy used to power growth, development, & movement.