MICROORGANISMS
VIRUSES, BACTERIA &
PROTISTS
VIRUSES
Chicken Pox
HIV
Influenza
Herpes
VIRUSES
What is a virus?
 A non-cellular particle made up
of genetic material that can
invade living cells.
 Viruses can grow and reproduce
but only with the help of a host.
STRUCTURE OF A VIRUS
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Capsid
DNA or RNA
tail
tail fibers
Bacteriaphage
Virus Diversity
Viruses are specific to the cells they
attack.
Ex. HIV only attacks white blood cells,
herpes only attacks cells of the lips or
genitals, bacteriaphages only attack
bacteria
 Ways of attacking cells; injecting DNA
into cell (bacteriaphages) or completely
entering the cell
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LIFE CYCLE OF A VIRUS
1. Attachment
 Virus attaches to a specific host cell
2. Entry
 virus injects cell with its own DNA
3. Replication
 host cell destroyed
new viral DNA and proteins made.
4. Assembly
 new virus particles assemble
5. Lysis and Release
 new virus particles released.
ARE VIRUSES LIVING?
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Biologists do not consider viruses living;
they do not belong to ANY kingdom.
Viruses can not live independently.
However, in a host, viruses can grow,
reproduce, regulate gene expression
and even evolve.
Should they be considered living?
#1
http://www.youtube.com/watch?v=D2Uuc
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 #2
http://www.youtube.com/watch?v=800F
BiTjaLY
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BACTERIA
BACTERIA
 Lack
a nucleus, single celled
 Heterotrophic and Autotrophic
 Identified by shape:
cocci - round
bacilli - rod
spirilla - spiral
Reproduction
Sexual reproduction
 conjugation
 A bridge forms
between 2 bacteria.
DNA is transferred
from one to the other
bacteria
Asexual Reproduction
 Binary fission
 No genetic
recombination
Domain Archaea
Kingdom Archeabacteria
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Ancient Bacteria
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Prokaryotic (no
organized nucleus)
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Have separate
evolutionary history and
biochemistry from other
bacteria.
Found in harsh
environments
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Domain Bacteria
Kingdom Eubacteria
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Ubiquitous (commonly
occurring) and diverse
Occur in every habitat
and environment on
earth, even acidic and
radioactive ones.
Most are harmless or
even beneficial but
some are pathogenic
(disease causing)
Ex. Bubonic Plague,
cholera, syphillus,
anthrax, and leprosy all
caused by bacteria.
Identifying Bacteria
2 Types:
1. Gram –
 Bacteria with a thin wall of
peptidoglycan
 Do not stain with Gram’s Stain
 Ex. N. gonorrhoea,
salmonella, E. Coli
2. Gram +
 Thick wall of peptidoglycan
 Staphyloccus, streptococcus
IMPORTANCE
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Fix nitrogen - break down nitrogen to
make it usable
Recycle nutrients - break down nutrients
of dead organisms returning the
nutrients to the environment.
Food and medicines - food formed from
fermentation (yogurt, cheese, butter)
Disease
Disease Transmission
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Word Scramble – In groups of 2
complete the word scramble cutouts.
Word Scramble Game
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: e, g, m, r
Word:
This word is a noun. This may not be seen, but it can make you sick! (Definition: a microorganism that causes
diseases.)
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: a, g, i, m, n, o, r, s
Word:
This word is a noun that ends with the suffix “-ism.” This refers to an individual form of life. (Definition: a
living being, a form of life considered as an entity.)
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: c, e, f, i, i, n, o, s, t, u
Word:
This word is an adjective. This can be used to describe a germ that spreads from person to person. (Definition: that
which corrupts or contaminates; spreading rapidly to others.)
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: c, e, f, i, n, t
Word:
This word is a verb. Germs do this to people and cause diseases. (Definition: affect, contaminate, taint.)
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: a, i, m, n, r, s, t, t
Word:
This word is a verb containing the prefix “-trans.” This describes the action when a germ is moved from
one person to another. (Definition: send, spread, pass on.)
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: a, i, i, m, n, n, o, r, s, s, s, t
Word:
This word is a noun. This happens not only to germs but also to radio waves. (Definition: an act or process of
spreading.)
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: a, d, e, e, i, s, s
Word:
This word is a noun. Some of this can be prevented by eating healthily and exercising daily. (Definition:
illness.)
Unscramble the letters to spell a word using the hint and definition on the right.
Letters: m, m, o, p, s, t, y
Word:
This word is a noun. A common cold shows this as a cough, sore throat, sneezing, headache, slight fever, runny
nose, etc. (Definition: a sign or indication of something)
Keep the words that you just unscrambled
in mind as we discuss the following
questions.
 1. What are some infectious diseases you
already know about and what are their
symptoms?
 2. What makes these diseases contagious?
 3. To help stop or minimize the transmission
of infectious diseases, what information do
you think would be important to know and
what are some precautions that one could
take?
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You will be simulating the transmission
of diseases from one person to another.
Each person will be given a cup with a
liquid in it.
You will exchange liquid with 3 partners
by combining then splitting the contents
of the 2 cups. Be sure to record who
you exchange with!
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When the class is finished we will add
phenolphthalein (C20H14O4) which is an
indicator of bases.
Phenolphthalein stays clear in water but
will turn pink in the presence of a
solution above 7 ph.
3 of the cups had a common base,
sodium hydroxide NaOH.
Let’s check your cup!
Now, in groups of 3 complete the
summary sheet.
Protists
KINGDOM PROTISTA
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Single celled
HAVE a nucleus
Reproduce
sexually - conjugation
asexually - binary
fission
autotrophic and
heterotrophic
Protista Classification
 PROTOZOANS
“Animal like”
 ALGAE
“Plant like”
 FUNGI
“Fungi-like”
PROTOZOANS
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Classified by movement
1. Pseudopodia - pseudopods
ex. Amoeba
2. Ciliates - cilia
ex. Paramecium
3. Flagellates - flagella
ex. Euglena
Algae
Classified by color
–ex. Blue green
algae