1. Nature’s Building Blocks
Cells

2. First discovered in 1665 by Robert Hook
Using a microscope, he looked at cork

3. Why did he call them cells?

7. All living organisms are composed of cells
Single celled organisms
Examples are amoebas, paramecia, protozoa, and bacteria
Bacteria are important!
Help digestion
Fix nitrogen
Cause fermentation
Cause disease

8. Amoebas

9. Protozoa

10. Bacteria

12. Multicelled organisms
Examples: People plants, etc.
Cells can come in many different shapes and sizes
Largest = ostrich egg
Smallest = need high powered microscope to see

13. Largest cell

14. Smallest cell

15. No really 
Lives freely in the ocean
Bacteria

16. Cell structure and Function
Plant and animals cells = two main
Cell wall = plant cells only
Made of cellulose in branches and stems
Made of pectin in fruits
Holds cells together
Gives plant structure

17. Osmosis = Diffusion of WATER
Cell membrane
Aka plasma membrane
Selectively permeable
Operates through diffusion
Diffusion = transfer of materials from high concentration to low concentration
Osmosis = Diffusion of WATER

18. Homeostasis = balance that cells strive to maintain (steak and dog example)
Turgidity = when a cell has the right amount of liquid (turgor & turgor pressure)

20. More cell parts….

21. Nucleus Prokaryotic cells = do not have one
Eukaryotic cells = have one (sometimes many)
Made of nucleic acids, enzymes, and proteins
Control center of the cell
Contains the genetic code (DNA)

23. Cytoplasm Thick clear fluid that surrounds the nucleus
Suspends other parts of the cell
Moves materials around to help keep the cell alive and functioning

25. Organelles The “mini organs” inside cells
They carry out cell functions

26. Mitochondria Shaped like a peanut
Break down nutrients from food and supply cell with energy
Cells that need less energy have a lower number of these
Known as the “powerhouse” of the cell

28. Vacuoles Vacuoles are specialized for different functions
Made of a membrane that holds H2O and other materials
All involve storage
Some store wastes from the cell
Some store nutrients and enzymes

30. Microtubules Are like bones
Thin, hollow tubes of protein that help give the cell structure
Aid in cell division
Make cilia and flagella

32. Microfilaments Fiber like structures
Wave back and forth to make a cell move

34. Ribosomes Where protein molecules are assembled
Proteins are a key component of enzymes

36. Golgi Apparatus Looks like flat sacs bundled together
Takes water out of protein and prepares it to leave the cell

38. Endoplasmic Reticulum
Webbed network of double membranes
Transports materials within the cell

40. Lysosomes Digest proteins, carbohydrates, and other molecules
Digests foreign invaders like bacteria
If other organelles quit working… digests them too!

42. Plastids Plant cells only 3 types
Chloroplasts = convert suns energy to carbohydrates, contain chlorophyll
Leucoplasts = store starch, proteins, and lipids, mostly found in seeds
Chromoplasts = creates pigments that give fruit its color

44. Centrioles
Centers that organize the microtubules within a cell