BIO 208 - Microbiology - Unit 1 - Lecture 1 - The Microbial World and ...

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1

BIO 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 Microbiology

biology



micro
-



A. What Are Microbes?





Microbes are:


bacteria


Domain Bacteria


archaea


Domain Archaea


protists


algae



Domain Eu
k
arya


fungi


B
.

Where Are Microbes Found?







C.

What Do Microbes Do?







Why
don’t microbes take over the planet?

1.

2.






2

BIO 208 Unit 1
-

The Microbial World and You

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




Chem
ical products




Biotechnology




Bioremediation




We are microbial ecosystems!




A
ssignment 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.




3

BIO 208 Unit 1
-

The Microbial World and 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 (1
st

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)
-



4

BIO 208 Unit 1
-

The Microbial World and You

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
-
406

1.
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
eu
k
aryotes


Assignmen
t 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)


5

BIO 208 Unit 1
-

The Microbial World and You

In Lecture 3 and 4 we will talk about how microorganisms are classified, some of the
similarities and differences among the major grou
ps 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 Eu
k
arya




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





6

BIO 208 Unit 1
-

The Microbial World and You

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

Eu
k
arya

Archaea

Bacteria

has a nucleus?

yes

no

no

DNA packaged with histones?

yes

yes

no

arrangement of membrane

bilayer

bilayer or
monolayer

bilayer

type of phospholipids

FA

No FA

FA

has peptidoglycan?

no

no

yes

FA = fatty acids


C
. What do we do with:

1. Viruses
-





2. Prions





BSE (
b
ovine
s
pongiform
e
ncephalopathy = mad cow disease)



Creutzfeldt
-
Jacob Disease (CJD and nvCJD)



Kuru







7

BIO 208 Unit 1
-

The Microbial World and You

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 m

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.









8

BIO 208 Unit 1
-

The Microbial World and You

D. Microscopy


1.

Light Microscopy (LM)
-



magnification
-


resolving power
-



a. Bright field





b. Dark field




Ex.


c.

P
hase
-
contrast





d. Fluorescence






Ex.


9

BIO 208 Unit 1
-

The Microbial World and You

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

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 a
nd 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.





10

BIO 208 Unit 1
-

The Microbial World and You

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

You m
ay 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 arrangement

a.
cocci

-






b. rods

-





c. spirals

-



11

BIO 208 Unit 1
-

The Microbial World and You

4.

Internal Structures

those c
ommon to
all

Bacteria and Archaea

a. cytoplasm
-






b. nucleoid (= nuclear region)





c. ribosomes
-





those f
ound
only in some

Bacteria and Archaea

d. plasmids
-






e. inclusions
-






f. endospores




Ex
s.
Bacillus

anthracis

Clostridium

botulinum


function
-



Processes of sporulation (spore formation)


Fig. 4.21

p. 97.

and germination.


12

BIO 208 Unit 1
-

The Microbial World and You

5. Plasma membrane (= cytoplasmic
membrane)

found in all cells



Archaea


glycerol


O


branched lipid



Bacteria


glycerol


O


C


CH
3



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

Yes

Can concentrate inside

No

No

Yes

Yes

Energy expended

No

No

Yes

Yes

Substance modified
during transport

No

No

No


Yes



O


13

BIO 208 Unit 1
-

The Microbial World and You

6. Cell Wall


Fig. 4.13

p. 8
6
.

found in a
lmost all Bacteria and Archaea have

Exceptions:
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
.








14

BIO 208 Unit 1
-

The Microbial World and You

7. Str
uctures External to Cell Wall

These
external structures are found in
many

but not
all Bacteria and Archaea


a. glycocalyx
-






functions

i.

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

Eu
k
aryotic

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

c
lass.




15

BIO 208 Unit 1
-

The Microbial World and You

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 Eukarya

1. 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


16

BIO 208 Unit 1
-

The Microbial World and You

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 cyanobacteria

b. surrounded by a membrane

c. have their own DNA

d. contain 70S ribosomes

e. 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 proteobacteria

b. surrounded by a membrane

c. have their own DNA

d. contain 70S ribosomes

e. grow and divide on their own schedule

f. some modern Eukarya do not ha
ve 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



Archea
e

have histones for organizing DNA, so do Eukarya



some Archea
e

have no cell walls, only a plasma membrane.


17

BIO 208 Unit 1
-

The Microbial World and You

T
he evolution of Eukarya from multiple mergers of Archaea

and Bacteria = The Theory of Serial
Endosymbiosis


Putting it to
gether in chronological order:


1.

Archaea attacked by spirochetes


2.

Archaea surrounded its DNA with membrane


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.