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Introduction to Microbiology

BIO 6

Denise Lim

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Use Your Textbook Wisely

Glossary and IndexAppendices"Check Your Understanding"Study Outlines

At end of chaptersReview and Study Questions at end of

chaptersAnswers in the back of the book

Some other words of advice

Manage your time wellPay attention to detailLearn to be a good communicatorBe professional

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What is Microbiology?

The study of organisms usually too small to see with the naked eyeRequires a microscope

Microorganisms include:Bacteria, archaea, fungi, protozoa,

algae, viruses, and animal parasites

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How small is small?

Why do we care about microbes?

Some can make us sick (germs)Most are beneficial

Important part of food chain: photosynthesis to decomposition (rot)

Found in our bodies (probiotics)Fermentation: cheese, yogurt, wine, beer,

vinegar, breadPharmaceuticals and medicine

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Binomial nomenclature(naming microorganisms)

Two names: Genus and speciesAlways italicized or underlined

Genus name: Always capitalizedUsually a noun

Species name:Always lower caseUsually an adjective, sometimes a

proper noun

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All living organisms are either prokaryotes or eukaryotes

Refers to arrangement of genetic material (DNA) in cellsPro - karyote means “before” nucleusEu - karyote means “true” nucleus

Prokaryotes have DNA spread throughout cytoplasm

Eukaryotes have DNA within a membrane bounded nucleus

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Prokaryotes are either bacteria or archaeaAll are single-celled organismsMost are much smaller (100 - 1000X

smaller) than eukaryotic cellsEukaryotes are everything else:

Fungi, protistans, plants and animalsCan be either single- or multi-celled

organisms

Prokaryotes vs. Eukaryotes

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Bacterial cell on left is 1000X smallerthan eukaryotic cell on right

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Size Comparison of two prokaryotes & a eukaryoteProkaryotes

Epulopiscium: 700 µm

Escherichia coli: 0.5 - 2 µm

EukaryoteParamecium:

50 µm

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Bacterial Virus (T4) Animal Virus (Ebola)

Are viruses living?

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Why are viruses nonliving?

NoncellularComposed of genetic material (either

DNA or RNA) surrounded by a protein coat

No metabolic capabilitiesCannot reproduce independentlyNo ability to regulate or respond

to environment

What features define life?Complex organization composed of cellsAbility to grow and developAbility to convert energy for own useAbility to reproduce genetically similar offspring

Presence of genetic material: DNA & RNA

Ability to regulate internal environment (homeostasis)

Ability to respond to environmental stimulus

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Important Historical Events: 1600's & 1700's

Development of the MicroscopeAnimicules visualized

Discovery of immunization & vaccines

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1800's

Development of Cell TheoryFermentation and PasteurizationGerm Theory of DiseaseAntisepsis and Disease

Importance of hand washingAntiseptics: chemical compounds that

could kill germs

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Robert Koch 1843 - 1910

Developed pure culture techniques

Proved that Bacillus anthracis caused the disease anthrax in cattleDeveloped Koch’s

Postulates: rules for proving a specific microbe caused a specific disease

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Application of Koch’s Postulates

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1900's

Discovery of penicillin and other antimicrobial agents

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Staphylococcus aureus inhibition by fungus Penicillium antibiotic

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1900'sDNA is the genetic moleculeGenetic Code - 1960’sCentral DogmaRecombinant DNA technology -

1970's & 1980'sHuman Genome ProjectPersonal “-omics”