bio 208 - microbiology - unit 1 - lecture 1 - the microbial ...people.cst.cmich.edu/alm1ew/208...

1BIO 208 Unit 1 - The Microbial World and You

Unit One – The Microbial World and You.

Lecture 1 we begin our discussion on microbiology. CH1: pp 1-6 Microbes in Our Lives (in detail) and pp. 16-21 Microbes and Human Welfare (skim)

I. What Is Microbiologybiology – micro -

A. What Are Microbes?

Microbes are:

bacteria Domain Bacteria

archaea Domain Archaea

protists

algae Domain Eukarya

fungi

B. Where Are Microbes Found?

C. What Do Microbes Do?

Why don’t microbes take over the planet?1.2.


D. Why Should We Study Microbiology? Relationship to other disciplines:

Human disease

Plant/animal/fish/ disease

Human (and plant, animal, fish, insect, etc) health

Food and drink production and safety

Chemical products

Biotechnology

Bioremediation

We are microbial ecosystems!

Assignment to complete before next class:• Surf through course blackboard and web site linked there• Email your TA

– Subject line “BIO 208 Assignment 1”– Tell your TA 2 things you noticed on the course BB/web site that you think will be

helpful, useful, or were interesting to you.


Lecture 2 - We will be talking about how Microbiology emerged as a modern science. CH 1: pp. 6-11 Brief History of Microbiology and pp. 405-406 Etiology of Infectious Disease.

II. How Did Microbiology Become A Science?

A. Discovery of Microbes

1. Ancient Chinese

2. Romans (1st Century BC)

*3. Antoni van Leeuwenhoek (1673) – “animalcules”

B. Battle Over Spontaneous Generation

1. Redi (1668)

2. Needham (1745) versus Spallanzani (1765)

*3. Louis Pasteur (1861) -

4. Tyndall (1877) -


C. Germ Theory of Disease – Diseases are caused by microbes

1. Bassi (1835) – 2. Berkeley (1845) – *3. Semmelweis (1840s) – childbed fever (Streptococcus agalactiae)

*4. Pasteur (1865) –

*5. Lister (1867) –

*6. Robert Koch (late 1880s) – one specific microbial agent causes one specific disease

1876 – Bacillus anthracis – anthrax

1882 – Mycobacterium tuberculosis – tuberculosis (TB)1883 – Vibrio cholera - cholera

Koch's postulates – described on pp. 405-4061. associate - 2. isolate - 3. inoculate - 4. re-isolate -

D. Microbial Effects on Matter (not in your text so take good notes)

1. Schwann (1837) –

2. Pasteur (1857-1860) –

3. Winogradsky and Beijerinck (1887-1905) – microbes are involved in C, N, and S biogeochemical cycles in soil and aquatic

environments bacteria have modes of metabolism very different from that of eukaryotes

Assignment to complete before next class (will not be collected)• CH 1 Chapter end study questions:

– Review: 1, 4, 5j, m, n, p, 6, 8– Multiple choice: 1-3– Critical thinking: 2– Clinical applications: 2

• Answers are available at The Microbiology Place (http://www.microbiologyplace.com/ see inside cover of your text)

http://www.microbiologyplace.com/


In Lecture 3 and 4 we will talk about how microorganisms are classified, some of the similarities and differences among the major groups of microbes, and how we see microorganisms using microscopes.

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 Spirogyra2. Protozoa – Ex. Paramecium

b. Kingdom Fungi

Morphology types:1. Yeasts – Ex. Saccharomyces

2. Molds – Ex. Rhizopus

3. Mushrooms


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 Eukarya Archaea Bacteriahas a nucleus? yes no noDNA packaged with histones? yes yes noarrangement of membrane bilayer bilayer or

monolayerbilayer

type of phospholipids FA No FA FAhas peptidoglycan? no no yes

FA = fatty acids

C. What do we do with:1. Viruses -

2. Prions – BSE (bovine spongiform encephalopathy = mad cow disease) Creutzfeldt-Jacob Disease (CJD and nvCJD) Kuru


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)1 m1 mm (millimeter) = 0.001 or 10-3 m1 m (micrometer) = 0.000001m or 10-6 m1 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 nmresolution maximum = 200 nm (0.2 m)

ultraviolet light = 100-400 nmresolution max. = 100 nm

electrons = 0.005 nmresolution max. = 0.2 nm

3. Refraction – bending of light as it passes from one medium to another of a different density.


D. Microscopy

1. Light Microscopy (LM) -

magnification - resolving power -

a. Bright field

b. Dark field

Ex.

c.Phase-contrast

d. Fluorescence

Ex.


2. Electron Microscopy (EM) -

a. Transmission Electron Microscopy (TEM)

r.p. = 0.2nmmg = 10,000-100,000x

b. Scanning Electron Microscopy (SEM)

r.p. = 20nmmag. = 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

I expect that you will do these assignments as they are assigned. This will help you keep up with the material so that you will be prepared for tests. But I will not collect these assignments. I expect that as a college student you will be self-motivated and not have to have due dates and grades to force you to keep up and be prepared.

We will not cover Ch. 2 so if your Chemistry is not so fresh please review Ch. 2 on your own.


In Lectures 4 and 5 we will cover the anatomy of Bacteria and Archaea

You may want to bring your text to class with you so you can look at and mark figures that we go over.

V. Functional Anatomy of Cells – CH 4

A. Bacteria and Archaea

1. Composition -

2. Size -

Ex. Thiomargarita namibiensis – “sulfur pearl of Namibia”

3. Shape and arrangementa. cocci -

b. rods -

c. spirals -


4. Internal Structuresthose common to all Bacteria and Archaeaa. cytoplasm -

b. nucleoid (= nuclear region)

c. ribosomes -

those found only in some Bacteria and Archaead. plasmids -

e. inclusions -

f. endospores –

Exs. Bacillus anthracisClostridium botulinum

function -

Processes of sporulation (spore formation) – Fig. 4.21 p. 97.and germination.


5. Plasma membrane (= cytoplasmic membrane)found in all cells

Archaea glycerol – O – branched lipid

Bacteria glycerol – O – C – CH3 – fatty acid

a. Function of plasma membrane

1) simple diffusion –

2) facilitated diffusion –

3) active transport –

4) group translocation –

Transport Compare and Contrast

Property Simple Diffusion

Facilitated Diffusion

Active Transport

Group Translocation

Carrier mediated No Yes Yes YesCan concentrate inside No No Yes YesEnergy expended No No Yes YesSubstance modified during transport

No No No Yes

O


6. Cell Wall – Fig. 4.13 p. 86.found in almost all Bacteria and Archaea haveExceptions: Mycoplasma (Bacteria)

Thermoplasma (Archaea)

a. Functions -

1) Bacteria – divide into 2 groups based on a cell wall molecule called peptidoglycan (old name = murein)

Gram positive

Gram negative

2) Archaea – do not have peptidoglycan, some have similar molecule called pseudomurein, or chondroitin sulfate, or protein.


7. Structures External to Cell WallThese external structures are found in many but not all Bacteria and Archaea

a. glycocalyx -

functionsi.ii.iii.

b. flagella -

function -

c. axial filament – function - Ex. Treponema pallidum

d. fimbriae - function - Ex. Neisseria gonorrhoeae

e. pili - function –

Our next topic is Eukaryotic cell evolution, if you do not feel very comfortable with Eukaryotic cell anatomy, then please read and study pp. 98-106 The Eukaryotic Cell before the next class.


Our focus in Lecture 6 is how the Eukaryotic cell evolved.

Your textbook does not contain much information on this topic; lecture will be your primary source of information.

B. The Eukarya1. Compare/contrast with Bacteria and Archaea

a. Major differences

b. Similarities

2. Origins of the Eukarya (p. 106 and lecture)

a. History of evolution of cells and cellular based life

Symbiosis = living together

Endosymbiont = living inside


b. Theory of Serial Endosymbiosis - Lynn Margulis*Eukarya evolved as a result of multiple mergers of Bacteria and Archaea.

How Eukarya may have evolved – in reverse chronological order (starting with most recent evidence)

1. Cholorplasts -

Evidence:a. same size as cyanobacteriab. surrounded by a membranec. have their own DNA d. contain 70S ribosomese. have same pigments as cyanobacteria

All organisms with chloroplasts have mitochondria – therefore, mitochondria evolved as organelles before chloroplasts did

2. Mitochondria -

Evidence:a. same size as proteobacteriab. surrounded by a membranec. have their own DNAd. contain 70S ribosomese. grow and divide on their own schedulef. some modern Eukarya do not have mitochondria but do have bacterial

endosymbionts

3. Flagella and cilia -

4. Centrioles -

Evidence for 3 & 4: “docking” flagella and centrioles of Eukarya have DNA and RNA there are protists that have flagella but do not have mitochondria

5. Nucleus -

Evidence: nuclear envelope is a lipid membrane Archeae have histones for organizing DNA, so do Eukarya some Archeae have no cell walls, only a plasma membrane.


The evolution of Eukarya from multiple mergers of Archaea and Bacteria = The Theory of Serial Endosymbiosis

Putting it together in chronological order:

1. Archaea attacked by spirochetes

2. Archaea surrounded its DNA with membrane à evolved into a nucleus

3. Captive internal spirochetes evolved into centrioles

4. Endosymbiotic proteobacteria evolved into mitochondria

5. External spirochetes evolved into flagella and cilia

6. Endosymbiotic cyanobacteria evolved into chloroplasts

Assignments to complete before Test 1.CH 4:

- Review: 2, 3, 4, 5, 6, 7a, b, c, d, e- Multiple Choice: 1, 6, 7, 8, 9- Critical Thinking: 2, 3- Clinical Applications: 2

This ends the lecture material for Test 1.

bio 208 - microbiology - unit 1 - lecture 1 - the microbial ...people.cst.cmich.edu/alm1ew/208...

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