1. C ELLS AND C ELL T HEORY Biology

2. C ELLS All living things are made of cells. A cell is the basic unit of structure that carries out function in living things. They form the parts of an organism and helps the organism to function.

3. D ISCOVERING CELLS The invention of the microscope made it possible to first see cells. Two scientists first observed cells in the 1660’s. Robert Hooke called them cells, meaning “small rooms”. Anton van Leeuwenhoek built microscopes and looked at things with them all the time. He found one-celled organisms.

4. C ELL T HEORY The cell theory is a widely accepted explanation of the relationship between cells and living things. 1. All livings things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from existing cells.

5. C ELL STRUCTURE There are tiny structures inside cells, called organelles. Organelles carry out specific functions within the cell.

6. G ETTING INTO THE CELL Cell Wall- The cell wall is a rigid layer that surrounds plant cells. Function- to provide support and protection for the cell. Cell Membrane- All cells have cell membranes. Function- Regulates what enters and leaves the cell and also provides protection and support.

7. T HE N UCLEUS Nucleus- “Control Center” of the cell, which contains DNA. Nuclear Envelope- A double membrane that surrounds the nucleus. Nucleolus- A small, dense region inside the nucleus where the assembly of ribosomes begins.

8. O RGANELLES IN THE CYTOPLASM Cytoplasm- “Jelly-like” portion of the cell outside the nucleus. It cushions the organelles and provides a medium for things inside the cell to move through. Mitochondria- “Powerhouse” of the cell. They convert the chemical energy stored in food into ATP (molecules that cells use for energy).

9. M ORE O RGANELLES IN THE C YTOPLASM Endoplasmic Reticulum- “Conveyor Belt” where proteins and other materials are assembled and exported from the cell. Ribosomes- Found throughout the cytoplasm, these small organelles make proteins!

10. M ORE ORGANELLES IN THE CYTOPLASM Golgi Bodies/Apparatus- “Packagers” that modify, sort, and package proteins and other materials. Chloroplasts- Found mostly in plants, they capture the energy from sunlight and convert it into sugar during photosynthesis.

11. E VEN M ORE O RGANELLES IN THE C YTOPLASM ! Vacuoles- “Storage” for water, salts, proteins, and carbohydrates. Lysosomes- “Garbage Disposal” that digests “junk” that would otherwise clutter up the cell.

12. H OLY C OW ! T HERE ’ S A LOT OF O RGANELLES ! Cytoskeleton- “Scaffolding” that helps support the cell. Centrioles- Found only in animal cells and used during cell division.

13. A NIMAL CELL DIAGRAM

14. P LANT CELL DIAGRAM

15. S PECIALIZED C ELLS There are many types of cells within your body, each has a specific function. Ex: Brain cells, nerve cells, red blood cells, immune cells, etc. In multi-cellular (more than one cell) organisms, cells are organized into tissues, organs, and organ systems. Nerve Cells  Nervous tissue  Brain  Nervous System

16. B ACTERIAL C ELLS Have cell walls and cell membranes. Contain cytoplasm and ribosomes. Bacterial cells do not have a nucleus or any other organelles!

17. R EVIEW Q UESTIONS 1. What are the main ideas of the cell theory? 2. Identify two structures found in plant cells that are not found in animal cells. 3. In what types of cells would you expect to find a lot of mitochondria? Why?

18. V IDEOS https://www.youtube.com/watch?v=BB5rvjZzgFU https://www.youtube.com/watch?v=dmCjuKtDi-4 https://www.youtube.com/watch?v=yKW4F0Nu- UY