1. Chapter 2
The Cell

2. 2-1 Cells: The Units of Life

3. The Microscope: A
Tool
Q: Why do scientists need to use
microscopes?
A: Cells are small

4. Before…

5. Compound Microscope
• Combines the
power of 2
lenses to enlarge
the image and
blend light
toward your eye

6. Eye piece lens X objective lens
10x X 4x = 40x Low power
10x X 10x = 100x Medium Power
10x X = 400x High Power
40x

7. Eyepiece or ocular lens
• Lens closest to the
eye

8. Objective Lens
• Lens closest to the
specimen or object

9. Nosepiece
• Objectives fastened
to this revolving
structure

10. Stage
• Where you place
your slide

11. Stage clips
• Hold slide in place

12. Body Tube
• Light travels through
here

13. Light Source
• Provides light

14. Diaphragm
• Regulates the light
reaching the
objective lens

15. Base
• Supports the
microscope

16. Arm
• Holds the body
tube, acts as a
handle

17. Coarse focusing knob
• Used to focus under
low power only

18. Fine focusing knob
• Used to focus under
high power only

19. A microscope reverses and inverts the
image of an object seen under it
Before
viewing
under the
microscope e
While
viewing e
under the
microscope

20. Things moving under a microscope are
actually moving in the opposite direction

21. Things moving under a microscope are
actually moving in the opposite direction

22. Stereoscopic light microscope
• Give you 3D
view of an
object
• Used to look at
thick things
light can’t pass
through

23. Electron Microscopes
• Can magnify
things more
than 300,000
times

24. Transmission electron microscope
• Used to study parts inside a cell

27. Scanning Electron Microscope
• Used to see the surfaces of whole objects

33. Cell Theory
1. All organisms are made up of
one or more cells
2. Cells are the basic units of
structure and function in all
organisms
3. All cells come from cells that
already exist

34. 2-2 Cell Structure

35. Living cells are dynamic and have
several things in common
• Membrane
• Cytoplasm (gel-like material)
• Nucleus (control center)

36. There are 2 basic types of cells
1. Prokaryotic – no nucleus
2. Eukaryotic – has a nucleus

37. Cell Membrane
• Structure that forms the outer
boundary of the cell and allows
only certain materials to move in
and out of the cell

39. Features of the cell membrane
• Flexible
• Double layer of fats with some
proteins scattered throughout

40. Cytoplasm
• Gel-like material inside the cell
membrane

41. Organelles
• Structures within the cytoplasm of
eukaryotic cells

42. Nucleus
• Structure that directs all the
activities of the cell
• Contains the DNA

44. Chromatin
• Made up of protein and DNA
(genetic blue print)

45. Endoplasmic Reticulum
• Folded membrane that moves
materials around in the cell
• Some have ribosomes on them,
some don’t

47. Ribosomes
• Make
proteins
• Some found
on ER
• Others in
cytoplasm

48. Golgi Bodies
• The packaging and secreting
organelles of the cell

50. Mitochondria
• Where food molecules are broken
down and energy is released

52. Lysosomes
• Digests wastes
and worn out
cell parts

53. Vacuoles
• Storage areas, store water, food, wastes
• Small in animals and large in plants

54. Cell Wall
• Rigid structure
outside the cell
membrane that
supports and
protects the
plant cell

55. Chloroplasts
• Organelles where light energy is
changed into chemical energy in
the form of a sugar called glucose
(C6H12O6)

57. Chlorophyll
• Chemical in chloroplasts that
traps light energy – reflects green
light

59. Bacterial Cells
• Prokaryotic
• Don’t have membrane – bound
organelles

60. Features of bacterial cells
• Cell wall and cytoplasm
• Single chromosome
• No nuclei
• Ribosomes

61. 2-3 Cell Organization

62. Nerve Cell
• Send impulses
through your
body

63. Red Blood Cells
• Can change
shape
• Flexible
• Move through
the duct work of
your blood
vessels

64. Plant Vessel Cell
• Transports
water and
minerals
throughout the
cell

65. Tissues
• Groups of similar cells that do
similar things
• Ex.) smooth muscle tissue

66. Organ
• A structure made up of different
types of tissues that work
together
• Ex.) stomach

67. Organ System
• A group of organs working
together to do a certain job
• Ex.) digestive system