BIO 208 Unit 1 Lecture 3
This outline is intended to facilitate your preparation for lecture. This outline will NOT
substitute for regular lecture attendance.
Lecture 3 - we will discuss the following topics:
III. How Are Microorganisms Classified?
A. Nomenclature (p.6)
B. Phylogenetic Relationships (pp. 273-282)
1978 – 3 Domains – Carl Woese (1978, 1990)
Domain -
1. Domain Eukarya
a. Kingdom Protista
1. Unicellular algae – Ex Spirogyra
2. Protozoa – Ex. Paramecium
b. Kingdom Fungi
Morphology types:
1. Yeasts – Ex. Saccharomyces
2. Molds – Ex. Rhizopus
3. Mushrooms
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BIO 208 Unit 1 Lecture 3
Domains Bacteria and Archaea
What do they have in common?
What are the differences?
2. Domain Bacteria
Ex. Escherichia coli
3. Domain Archaea
Ex. Halobacterium salinarium
Comparing general characteristics of the 3 Domains
Domain
has a nucleus?
has histones?
arrangement of membrane
Eukarya
yes
yes
bilayer
type of phospholipids
has peptidoglycan?
FA
no
Archaea
no
yes
bilayer or
monolayer
No FA
no
C. What do we do with:
1. Viruses -
2. Prions –
 BSE (bovine spongiform encephalopathy = mad cow disease)
 Creutzfeldt-Jacob Disease (CJD and nvCJD)
 Kuru
Bacteria
no
no
bilayer
FA
yes
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BIO 208 Unit 1 Lecture 3
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IV. Observing Microbes With Microscopes
CH 3 p 55 Units of Measurement and pp 55-65 The Instruments
A. What problems need to be overcome to see a microorganism?
B. Units of measurement (you should be very comfortable with these; and converting
back and forth)
1m
1 mm (millimeter) = 0.001 or 10-3 m
1 m (micrometer) = 0.000001m or 10-6 m
1 nm (nanometer) = 0.000000001 m or 10-9 m
C. Properties of Light in Relation to Microscopy
1. Light - waves (wavelength = )
2. Resolution – ability to see 2 things that are close together as 2 separate & discrete things
visible light  = 550 nm
resolution maximum = 200 nm (0.2 m)
ultraviolet light  = 100-400 nm
resolution max. = 100 nm
electrons  = 0.005 nm
resolution max. = 0.2 nm
3. Refraction – bending of light as it passes from one medium to another of a different density.
BIO 208 Unit 1 Lecture 3
D. Microscopy
1. Light Microscopy (LM) magnification resolving power a. Bright field
b. Dark field
Ex.
c. Phase-contrast
d. Fluorescence
Ex.
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BIO 208 Unit 1 Lecture 3
2. Electron Microscopy (EM) a. Transmission Electron Microscopy (TEM)
r.p. = 0.2nm
mg = 10,000-100,000x
b. Scanning Electron Microscopy (SEM)
r.p. = 20nm
mag. = 1,000-10,000x
Comparison of LM and EM
Light Microscopy
Electron Microscopy
Illumination
Light
Electrons
Objective Lens
Glass
Electromagnetic
Ocular Lens
Glass
Electromagnetic Projector
Visualize
Through eye piece
On view screen
Assignment to complete before next class
 CH 10: Multiple Choice 3, 4
 CH 3: Review 1, 4, 6, 7, 8, 9
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