1. HOMEOSTASIS

2. Understanding Homeostasis at the Cellular Level
CELL THEORY AND STRUCTURE

3. Cell Theory All living things are made of cells
Cells are the basic unit of structure and function in an organism (basic unit of life)
Cells come from the reproduction of existing cells (cell division)

4. History of Cells & the Cell Theory
In 1665, Robert Hooke used a microscope to examine a thin slice of cork (dead plant cell walls)
What he saw looked like small boxes
Hooke is responsible for naming cells
In 1673, Leeuwenhoek was first to view living organisms
Leeuwenhoek used a simple, handheld microscope to view pond water & scrapings from his teeth

5. SCHLEIDEN, SCHWANN & VIRCHOW
In 1838, a German botanist named Matthias Schleiden concluded that all plants were made of cells
In 1839, a German zoologist named Theodore Schwann concluded that all animals were made of cells
In 1855, a German medical doctor named Rudolph Virchow observed, under the microscope, cells dividing
He reasoned that all cells come from other pre-existing cells by cell division

6. Remember Endosymbiotic Theory
In 1970, American biologist, Lynn Margulis, provided evidence that some organelles within cells were at one time free living cells themselves – this is called Endosymbiotic Theory
Chloroplasts and mitochondria were the organelles she pointed to as evidence of this theory
Chloroplast and Mitochondria have their own DNA which is different from the DNA of the cell

7. Number of Cells Unicellular – composed of one cell Ex: bacteria, yeast
Multicellular - composed of many cells that may organize
Ex: butterfly, flower

8. Prokaryotes Have a nucleoid region contains the DNA (no nucleus)
Have a cell membrane & cell wall
Contain ribosomes to make proteins in their cytoplasm

9. Eukaryotic Cell Contain 3 basic cell structures:
Nucleus (containing DNA)
Cell Membrane
Cytoplasm with organelles

10. Two Main Types of Eukaryotic Cells
Plant Cell
Animal Cell

11. Organelles Called the “organs” of cells Very small in size
Have specific functions
Found in cytoplasm of cell

12. Lysosome Contain digestive enzymes
Break down food and worn out cell parts

13. Nucleolus
Inside nucleus
Produces the ribosomes that make proteins

14. Smooth & Rough Endoplasmic Reticulum
Smooth ER - lacks ribosomes & detoxifies poisons and synthesizes lipids
Rough ER - has ribosomes on its surface & makes proteins to EXPORT

15. Mitochondria
Site of Cellular respiration – the capturing of energy from food
Breaks down glucose to produce energy ATP

16. Plant Cell Organelles Chloroplast
Process called photosynthesis occurs here

17. Plant Cell
Cell wall
Made of cellulose
Found in plant cells

18. Plant Cell Organelles
Vacuole
Have a large central vacuole

19. Animal Cell Organelles
Glycogen is stored in the cytoplasm of animal cells for food energy
glycogen granule

20. Animal Cell Organelles
Near the nucleus in an animal cell
Help cell divide

21. What are the basic parts of all eukaryotic cells?
Have a cell membrane surrounding the cytoplasm
Have membrane-bound organelles
Have a nucleus

22. Differences between plant cells and animal cells
Relatively small in size
Relatively large in size
Irregular shape
Regular shape
No cell wall
Cell wall present

23. Differences between Plant Cells and Animal Cells
Vacuole small or absent
Large central vacuole
Glycogen as food storage
Starch as food storage
Nucleus at the center
Nucleus near cell wall