1. Topic 3- Cells & Tools Used in the Lab

2. What is the difference between a theory and a law?
Theory- Not definite or proven, but is backed by scientific evidence.
Law- Definite, proven and is supported by scientific evidence.

3. Cell Theory: (3 parts) All living things are composed of cells.
1. Cells are the basic unit of structure.
2. Cells are the basic unit of function.
3. Cells come from pre-existing cells MITOSIS

4. Levels of Organization
Organelle: part of the cell
Cell: basic unit of living things
Tissue: made of a group of cells
Organ: made of several tissues
Organ System: composed of a group of organs
Organism: a living thing

5. Levels of Organization

6. Cell Models: An Interactive Animation

7. Animal Cell

8. Plant Cell

9. Cell Organelles (Parts of the Cell) Organelles Common to BOTH Animal & Plant Cells:

10. 1. Cell/Plasma Membrane:
1. surrounds all cells
2. regulates what goes into and out of the cell - semipermeable

11. The Cell Membrane is labled A in both pictures

13. 2. Nucleus: (contains DNA/RNA)
Controls the functions of the cell. It has a membrane of its own (nuclear membrane). [Brain]
Letter B - Nucleus

14. Found within the nucleus. Allows RNA to enter the cell.
3. Nucleolus:
Found within the nucleus. Allows RNA to enter the cell.
Dark circle w/in B - nucleolus

15. 4. Cytoplasm: Jelly-like fluid containing other organelles
It moves in a circular motion- CYCLOSIS.

16. 5. Endoplasmic Reticulum E.R. :
Channels - Aids in transport.
Can be smooth or rough
Rough- contains Ribosomes

17. Letter B - is the Endoplasmic Reticulum

18. 6. Ribosomes:
Site of protein synthesis. Can be free or attached to the E.R.
Letter C - Ribosomes

19. 7. Mitochondria: Site of cellular respiration  ATP=ENERGY.
[Powerhouse]

20. 8. Golgi Bodies/Apparatus/Complex:
Stacks of flattened tubes that package wastes in the cell. [Garbage Men]

21. 9. Vacuoles: STORAGE
Holds water or food. LARGE in a plant cell. small in an animal cell.
[Storage Bin]
Vacuole
Letter A - Vacuole

22. Organelles only in ANIMAL CELLS:
Lysosomes: Digests food or old, worn out parts of the cell. “Suicide Sacs”
Centrioles: Aids in cell division. Come in pairs.

23. Organelles only in PLANT CELLS:
Chloroplasts: Contains chlorophyll traps light and allows plants to make food  PHOTOSYNTHESIS
Cell Wall: Non-living structure that supports and protects the cell. Composed of cellulose.

24. Letter C – Cell Wall
Letter B – Chloroplasts - Photosynthesis

25. Tools & Techniques Used In the Lab:

26. Microscopes Image is upside down & backwards.
If you need to center a specimen,
move the slide in the opposite direction.

27. Types of Microscopes Compound Light Microscope:
2 sets of lenses (ocular & objective)
Specimens must be thin & transparent

28. Compound Microscope

29. Total Magnification
Eye piece x Objective lens = Total Magnification

30. Calculating Total Magnification
What is the total magnification under low power?
10 * 15 = 150x
What is the total magnification under high power?
10 * 45 = 450x

31. Focusing: Put slide on stage Turn to low power obj.
Use coarse adj. knob to focus
Turn to high power
Use fine adj. knob to focus
* Never use coarse adj. knob under high power  you could crack the slide

32. Move decimal point 3 places to the RIGHT
Microscope Measurement- The unit of measurement used with the microscope is the micron (um) mm=1,000 um
1. When converting mm  um
Move decimal point 3 places to the RIGHT
5mm=5,000 um
2. When converting um  mm
Move decimal point 3 places to the LEFT
9,000um=9mm

33. Which neuron is the longest?
How long is one cell in Micrometers?

34. In um, approximately how long is the paramecium?

35. Field of View- When you look in the ocular, it is the view you see.
HIGH POWER FOV is 4x smaller than low power FOV.
You will see less cells, but more detail.
High power is darker than low power.
LOW POWER FOV is 4x LARGER than high power FOV.
You will see more cells, but less detail.
Low power is brighter than high power.

36. Field of View (FOV)

37. Microscope Measurements:
Q: If you can see 20 cells under low power FOV, how many will you see under high power FOV?
LOW POWER  HIGH POWER ( / 4)
20 / 4 = 5 cells under High power
Q. If you can see 2 cells under high power FOV, how many will you see under low power FOV?
HIGH POWER  LOW POWER (X 4)
2 x 4 = 8 cells under Low power

38. More Tools & Techniques Used in the Lab:
1. Stereomicroscope/ Binocular / Dissecting Microscope:
2 eyepieces
look at opaque objects

39. 2. Electron Microscope
- uses beams of electrons and magnets
- specimens thin and dead
- view inside mitochondria or ribosomes
- extremely powerful

40. Microdissection Instruments:
Dissection of cells
Can be used to transplant a nucleus from one cell to another

41. Stains: Makes organelles more visible Iodine- yellow stain
Methylene Blue (vital/living) - blue stain

42. Centrifuge: Spins contents at a high speed
Separates contents by density
Heaviest- bottom Lightest- top

43. Chromatography:
Separates pigments/colors at different rates

45. Gel Electrophoresis:
Used to separate substances that have an electrical charge
Substance is cut using an enzyme
Substances are placed into wells located at the top of the gel
Substances separated based on their size and charge
Small particles travel further through the gel, large particles do not
Can be used to separate fragments of DNA

46. Gel electrophoresis