1. Cells

2. Homeostasis
Cells work together to maintain homeostasis. Cells have different functions.
Homeostasis = stable environment in your body; balance
Your body maintains its homeostasis even if outside conditions are changing.

3. Levels of Organization
Tissue- group of similar cells working together
Organ- two or more tissues that work together
Organ system- two or more organs that work together
Organism- has multiple organ systems that work together to maintain homeostasis in the entire body

4. Least to Most Complex (5 Levels)
Cell  Tissue  Organ  Organ System Organism

5. Cell Size We need a microscope to see most cells. Onion cell
Cork cells
Plant cell
Animal cell

6. Why are cells so small?
If cells get too big, they cannot take in enough nutrients or get rid of enough wastes.
This happens since a cells volume will grow faster than its surface area.

7. All cells have:
Cell Membrane: Layer that covers cell’s surface and acts as a barrier between inside of cell and its environment
Cytoplasm: The fluid inside a cell
DNA: The genetic material that carries information needed to make new cells/organisms
Ribosomes

8. Cell Theory All organisms are made of one or more cells
The cell is the basic unit of all living things
All cells come from existing cells

9. Copy this chart in your composition book
Copy this chart in your composition book. Work with your partner to complete the chart.

10. Matthias Schleiden Theodor Schwann Rudolf Virchow Robert Hooke
Describe how each of these people helped us understand cells and/or what they discovered.
Matthias Schleiden
Theodor Schwann
Rudolf Virchow
Robert Hooke
Anton van Leeuwenhoek

11. Two Types of Cells Prokaryotes (Pro/No) Single-celled organisms
Smaller
Do NOT have a nucleus or organelles
Ex: bacteria, archaea
Pro means before and kary means nucleus

12. 2. Eukaryotes (You) Can be single or multi-cellular Larger
Have a nucleus and organelles
Ex: animals, plants, fungi
Eu means good or true and kary means nucleus

15. Plant and animal cells are eukaryotic.
Eukaryotic cells are complex and made of many parts.

16. Cell Wall only in plant and fungi cells
Its purpose is to shape and protect the cell.
“Supporter and Protector”

17. Chloroplast Only in plant cells Green
Contains chlorophyll, which captures energy from sunlight and uses it to produce food for the cell (photosynthesis)
“Food Producers”

18. Cell Membrane The cell membrane holds and protects the cell.
It controls what substances come into and out of the cell
“Gate of the Cell”

19. Cytoplasm
The cytoplasm is the watery, gel- like material in which cell parts move and cell activities take place

20. Mitochondria Where energy (ATP) for the cell is made
“powerhouse of the cell”

21. Vacuole The vacuoles store food, water, and chemicals “Storage Tanks”
One large one in plants & multiple small ones in animals

22. Ribosomes Make proteins Small and round
Only organelle not covered by a membrane

23. Endoplasmic Reticulum (ER)
Rough ER has ribosomes attached to it
Smooth doesn’t
ER is folded and located by the nucleus
Transports cell materials and delivers protein to the Golgi apparatus

24. Golgi Apparatus
packages and distributes proteins and other materials out of cell
folded

25. Nucleus
The nucleus regulates and controls cell activities, acting like the “brain” of the cell
Contains chromosomes
“Control Center”

26. Nucleolus
Where cells make ribosomes
Located in the nucleus

27. Lysosomes Digests and get rid of waste
Destroy worn-out or damaged organelles
Protect the cell from foreign invaders
Found in animal cells

28. Centrioles
Located in animal cells
Used for cell division (mitosis)