1. Chapter 7
CELLS

2. DISCOVERY
Robert Hooke examined a slice of cork and saw little boxes he called “cells”

3. DEFINITION
CELL- the smallest unit of matter that can carry on all the processes of life
(Plants, animals)
Plant cells discovered by SCHLEIDEN in 1838
Animal cells discovered by SCHWANN in 1855

4. CELL THEORY- 3 parts
1. all living things are made of one or more cells
2. cells are the basic units of structure and function in an organism
3. cells come only from the reproduction of existing cells

5. CELL DIVERSITY
SIZE- cells are limited in size by the ratio between their outer surface area and their volume
Nutrients, oxygen, and other materials must pass through the surface of the cell

6. CELL DIVERSITY
SHAPE- cells come in a variety of shapes to best fit their function
Example Nerve Cell- long and slender with many branches
White Blood Cell- can change shape, leave blood, and engulf bacteria

7. CELL DIVERSITY
INTERNAL ORGANIZATION-cells contain a variety of structures called ORGANELLES
ORGANELLES- “little organ”- performs specific functions for the cell

8. ORGANELLES
CELL MEMBRANE- thin membrane that separates the cell from its environment

9. ORGANELLES
NUCLEUS – large dense area near the center of the cell that controls all the cells functions and carries hereditary information
EUKARYOTES ---“ true” “nucleus”- organisms whose cells have a membrane bound nucleus and other organelles
Examples-
PROKARYOTES- organisms that do not have a membrane bound nucleus

10. ORGANELLES
CELL WALL- (CELLULOSE) –rigid structure on the outside of the cell membrane of plant cells. Provides structure and protection for the cell

11. ORGANELLES
CYTOPLASM- liquid portion of the cell (up to 80% water) location of many chemical reactions

12. ORGANELLES
MITOCHONDRIA- double membraned cell with CRISTAE (waves)-produces energy for the cell (ATP)

13. ORGANELLES
ROUGH ENDOPLASMIC RETICULUM- sets of tubules located near the nucleus that are lined with ribosomes- synthesizes proteins

14. ORGANELLES
SMOOTH ENDOPLASMIC RETICULUM- sets of tubules located near the rough ER that are without ribosomes- synthesizes fats, breaks down toxins

15. ORGANELLES
RIBOSOME- tiny dots found on the Rough ER (or floating around) that synthesize protein

16. ORGANELLES
GOLGI APPARATUS- (UPS of the cell) flattened stacks of membranes that receive, package, and transport materials throughout the cell

17. ORGANELLES
LYSOSOME- (garbage disposal of the cell) vesicles filled with digestive enzymes. Breaks down dead cell parts, bacteria invaders, food.

18. ORGANELLES
PEROXISOMES- vesicles filled with enzymes used to detoxify the cell

19. ORGANELLES
CYTOSKELETON- network of long proteins that give the cell structure and move items around in the cell

20. ORGANELLES
MICROTUBULES-long hollow tubes that provide support for the cell- helps in cell division

21. ORGANELLES
MICROFILAMENTS- thin fibers of protein that help in movement of the cell and aide in contraction of muscle cells

22. ORGANELLES
CENTRIOLES- specialized microtubules around the nucleus that helps with the division of the nucleus

23. ORGANELLES
CHLOROPLASTS- double membraned organelle that collects light and makes glucose (PHOTOSYNTHESIS)

24. ORGANELLES
CHLOROPHYLL- green pigment in chloroplasts that absorb visible light

25. ORGANELLES
VACUOLES- large vesicle (in plants) and smaller in animals- that store fluids such as – enzymes, water, wastes, ions, food

26. ORGANELLES
FLAGELLA- long whip like tail filled with microtubules that are used for motility.

27. ORGANELLES
CILIA- small hairlike structure made of microtubules that aide in motility or collects food