1. Cell Structure and Function
Chapter 4

2. Microscopes
Create detailed images of something that is otherwise too small to see
Light microscopes
Simple or compound
Electron microscopes
Transmission EM or Scanning EM

5. MICROSCOPE CHART Living Non-living
TYPE OF MICROSCOPE
DESCRIPTION
MAGNIFICATION RANGES
TYPE OF SPECIMEN
Compound Light Microscope
(LM)
Shines light through the specimen and a series of lenses magnifying a colored 2-D image in open air.
Low magnification and resolution
SOURCE OF RADIATION: light
~ 20X to 1000X
Living
Non-living
Scanning Electron Microscope
(SEM)
Shines a beam of electrons (like the light) on the surface of a specimen (like the slide) in a vacuum and the scanned black-and white, 3-D image is projected onto a screen for viewing.
High magnification and resolution
SOURCE OF RADIATION: electrons
~ 10x to 200,000x
Non-living solid objects such as preserved cells, organelles, cloth, etc.
Transmission Electron Microscope
(TEM)
Shines a beam of electrons (like the light) through a specimen (like the slide) in a vacuum and the transmitted black-and-white, 2-D image is projected for viewing.
~ 50X – 50,000,000X
Ultra-thin slices
stained with a heavy metal salt to provide contrast

6. In-text, p. 54

8. Limitations of Light Microscopy
Wavelengths of light are nm
If a structure is less than one-half of a wavelength long, it will not be visible
IF TOO SMALL  LIGHT CAN’T PASS THROUGH IT  can’t see it

9. which 2 ways does the LM turn its image?
If you see this on slide, r
upside down
flipped r r
Then you’ll see this in the microscope

10. What are the 3 things that LM do to images?
Flip
Invert
magnify

11. Estimate the actual size of this cell.
ratio:
100mm x
Diameter of power
Width of “thing”
Width of circle =
45mm 45 x =
100x
100 5
Low
2mm
High
.5mm
Oil immers
.2mm x
2.25mm =
2,250micrometers

12. Electron Microscopy
Uses streams of accelerated electrons rather than light
Electrons are focused by magnets rather than glass lenses

14. ~45x SEM

18. -of a 2.5 nm small gold cluster in 1982
TEM Images
Au atoms
The First Atom Image !
-of a 2.5 nm small gold cluster in 1982

20. <<LINK>>
Important events in the discovery of cells:
Robert Hooke: (1665) Examined shredded bark of oak trees (cork): observed boxlike units which were empty inside. He called these units “cells”. He described them as being “walls of enclosed space, such as a box. He believed that only plants were made of cells
b) Anton van Leeuwenhoek: (1673) microscope maker, studied organisms living in pond water, saw first unicellular organisms
c) Henri Dutrochet : (1824) was the first to suggest that all living things are composed of cells
<<LINK>>

22. Anton von Leeuwenhoek

23. d) Robert Brown: (1831) identified a structure within the fluid of a plant cell – THE NUCLEUS. He didn’t identify its function
I discovered the NUCLEUS..
Nah, I’m just messin’
I FEEL GOOD .. OW!

24. II. Developing Cell Theory
e) Matthias Schleiden: (1838) German botonist that observed plant cells. He suggested that all plant tissue was made up of cells and expanded on Brown’s work by suggesting the nucleus plays a role in cell reproduction

25. f) Theodor Schwann: (1839) German zoologist who observed animal cells and found that animal tissue resembled plant tissue. He concluded that the cell was the basic unit of animal.
g) Rudolf Virchow: (1855) All plant and animal cells are produced from the division of other cells

28. why did it take so long to learn about cells?
Scientists had to build off each other’s ideas
Had to wait for stronger technology
Culture/religion inhibiting progress

29. III. Cell Theory a) All organisms are composed of one or more cells
b) The cell is the basic unit of structure and function in all living things (anything smaller than a cell is not alive)
c) Cells arise by division from pre- existing cells

30. IV. Cell Size
Range from largest cell (ostrich egg) to bacterial cells (need a microscope)
Limited to being … small

32. Why Are Cells So Small? Surface-to- volume ratio
The bigger a cell is, the less surface area there is per unit volume
Above a certain size, material cannot be moved in or out of cell fast enough

41. red went the furthest in

42. Cells need to be SMALL so they could all FIT in/on the organism!
HOW MANY CELLS ARE THERE IN A HUMAN BODY????
10 QUADRILLION!
There’s more bacteria than your body cells!..

43. IV. Cell Shape Shape has to do with function
Ex. Skin, nerve, white blood cells
Change shape
To engulf

44. V. Other Features of Cells
Highly complex internal structure made up of organelles
Have genetic information
(DNA  RNA  make proteins that make up YOU)
Can get and use energy
Photosynthesis
Cellular respiration

45. Can metabolize – make up and break down of molecules in reactions
Can move (even organelles) / respond to stimuli (light, touch..etc)

46. 2. Cytoplasm – fluid filled cell interior
f. All cells contain the following 3 structures:
1. Plasma Membrane – separates the cell from the external environment
2. Cytoplasm – fluid filled cell interior
3. Nuclear area – genetic information stored as DNA

47. VI. 2 Types of Cells: a. Prokaryotes (prokaryotic) cells:
1. Pro = before karyon = nucleus
2. Size relative to eukaryotes?
small (5 – 10 um)
3. lack membrane-bound organelles (no nucleus, vacuoles, ER…)
4. NO nucleus, NUCLEIOD instead
5. most primitive type of cell
6. Includes what 2 Domains?
Bacteria and Archeobacteria

48. Prokaryotic Cells Domains: Archea and Bacteria
DNA is NOT enclosed in nucleus
Generally the smallest, simplest cells
No organelles

50. Prokaryotic Structure
nucleoid
cytoplasm
with ribosomes
DNA
flagellum
capsule
cell wall
plasma membrane

52. Pilus attachment to bladder

53. Eukaryotes (eukaryotic) cells:
1. Eu = true karyon = nucleus
2. size: larger than prokaryotes
3/4. contains a true nucleus and membrane-bound organelles
5. evolved from prokaryotes by ENDOSYMBIOTIC association of two or more prokaryotes (Mitochondria & Chloroplasts)
6. Includes what kingdoms?:
Protists, Fungi, Animal, and Plant

55. 3 DOMAINS 4 Kingdoms Archae Bacteria Prokarya Eukarya animal plant
protist
? are 3 main types of cells?
fungi

56. Prokaryotic Structure
nucleoid
cytoplasm
with ribosomes
DNA
flagellum
capsule
cell wall
plasma membrane

57. Animal Cell Features Plasma membrane cytoplasm Nucleoplasm Nucleolus
Nuclear membrane
Nuclear pore
Ribosomes
Rough ER
Smooth ER
Golgi body
Vesicles
Mitochondria
Cytoskeleton
Centrioles
Animal Cell Features

58. Check your answers! Microtubules Cytoplasm Vesicles/vacuoles
Nuclear membrane
Nuclear pores
Nucleoplasm
Rough ER
Smooth ER
Golgi Body
Vesicles
Cell membrane
Mitochondria
Centrioles
nucleolus

59. Properties of a Eukaryotic cell
Plant cell

60. Check your answers! Cell wall Cell membrane Mitochondria Chloroplast
Central vacuole

61. DIFFERENCES Plant Has: Animal Has:
CENTRAL VACUOLE
CHLOROPLASTS
CELL WALL
LYSOSOMES
CENTRIOLES
(and CILIA & FLAGELLA ----DUH! Because plants can’t move. ;-)

62. RNA copying from DNA

63. Ribosomes making amino acids

64. POLYPEPTIDE CHAIN IS FORMING…

65. ENDOSYMBIOTIC THEORY by Lynn MARGULIS
Mitochondria & Chloroplasts look like bacteria
Have own DNA
Have double membrane
Divide on their own
Chloroplasts and mitochondria USED TO BE BACTERIA! They gave the big cell ENERGY, the big eukaryotic cell gave them PROTECTION

67. 4.3 MULTICELLULAR ORGANIZATION

69. 3.5 billion yrs ago – 1st life forms!
ARCHAEA
BACTERIA
heat
methane gas
sulfur gas
what is the energy source?

70. Alexander Ivanovich Oparin (publ 1936), a Russian scientist, described hypothetical conditions which he felt would have been necessary for life to first come into existence on early Earth.
He thought the atmosphere was made largely of (H2O), (CO2), (CO), (N2), (CH4), and (NH3).
As the surface of Earth cooled again, torrential rains of this mixture formed the first seas, the “primordial soup.” Lightening, ultraviolet (UV) radiation, and volcanic action all were more intense than they are now.

72. What is an example of archaea bacteria?
EXTREMEOPHILES
- live in extreme environments

73. 2.5 billion yrs ago – 2nd living thing
CYANOBACTERIA
(blue-green “algae”)
what is the energy source?
sun
yay OXYGEN!

74. millions* yrs ago (recently)
PROTISTS
Unicellular organisms
algae
amoeba

76. millions* yrs ago (recently)
PROTISTS
MULTICELLULAR tiny organisms
seaweed

77. lichens
yay SOIL!

78. millions* yrs ago (recently)
PLANTS
ANIMALS (consumers)
FUNGI
DINOSAURS
US!

79. Colonial organism  uni to multicellular?
Made up of identical cells with specialized functions
Ex. VOLVOX

80. Lungfish  water to land?

81. THE ORGANIZATION OF LIFE!
ARE YOU READY FOR…
THE ORGANIZATION
OF LIFE!

82. living things have organization?
Space
universes
galaxy
Solar system
Earth
Biosphere
Ecosystem
Community
Population
Species
organism
Organism
Organ systems – ex:
Organ – ex:
Tissue – ex:
Cell
Organelles
Molecules
Elements
Atoms
P, N, E
Quarks ?
living things have organization

83. WHAT IS THE POINT OF LIFE?
To just exist?
To make a higher power happy?
To do our best?
To have lots of sex?!

84. ORGAN SYSTEMS Respiratory Digestive Excretory Skeletal Muscular
Nervous
Reproductive
Endocrine
Immune
Circulatory
Integumentary

85. ORGANS bladder apple skin lung root heart brain leaf Respiratory
Digestive
Excretory
Skeletal
Muscular
Nervous
Reproductive
Endocrine
Immune
Circulatory
Integumentary
skin
lung
root
heart
brain
leaf

86. TISSUES
EPITHELIAL
MUSCLE
NERVOUS
CONNECTIVE

87. LET'S PLAY:
NAME
THAT
DUDE !

88. Schleiden – plant dude

89. Virchow – cells come from pre-existing cells dude

90. Brown – nucleus dude

91. Hooke – cell guy

92. Dutrochet – all living things made up of cells

93. Leeuwenhoek – microscope dude

94. Lynn Margulis – endosymbiotic theory

95. Composite Animal Cell Flagella nucleolus Nucleus Chromosomes
Ribosomes
Endoplasic
reticulum
Microtuble
Mitochondrion
Picture adapted from Access Excellence’ rescource center:
Golgi apparatus
Centrioles
Cillia
Composite Animal Cell