microbio ch. 1

What are microorganisms?

Organisms too small to be seen with the unaided eye.

What does the term germ refer to?

A rapidly growing cell.

Are most microorganisms harmful or beneficial?

Beneficial.

List two beneficial roles of microbes.

Decompose waste; produce food or chemicals.

What percentage of microbes are pathogenic?

Only a small fraction.

Why is knowledge of microorganisms important in medicine?

It helps prevent disease and contamination.

Who developed scientific nomenclature?

Carolus Linnaeus.

How many names are used in scientific nomenclature?

Two.

What are the two parts of a scientific name?

Genus and specific epithet.

How should scientific names be written?

Italicized; genus capitalized, species lowercase.

After first use, how may scientific names be abbreviated?

First letter of genus plus species.

What does Escherichia coli mean?

Named after Escherich; coli refers to colon.

What type of cell are bacteria?

Prokaryotic.

What is the bacterial cell wall made of?

Peptidoglycan.

How do bacteria reproduce?

Binary fission.

How are archaea different from bacteria?

They lack peptidoglycan.

Where do archaea often live?

Extreme environments.

Are fungi prokaryotic or eukaryotic?

Eukaryotic.

What is the fungal cell wall made of?

Chitin.

Name three types of fungi.

Molds, mushrooms, yeasts.

Are protozoa unicellular or multicellular?

Unicellular.

Do protozoa have cell walls?

No.

How do protozoa move?

Pseudopods, cilia, or flagella.

How do algae obtain energy?

Photosynthesis.

What is the algal cell wall made of?

Cellulose.

Why are viruses not considered living organisms?

They cannot replicate independently.

What genetic material do viruses contain?

DNA or RNA.

What are helminths?

Multicellular parasitic worms.

Who first observed live microorganisms?

Anton van Leeuwenhoek.

What theory stated life arises from nonliving matter?

Spontaneous generation.

Who disproved spontaneous generation?

Louis Pasteur.

What did Pasteur's swan-neck flask demonstrate?

Microbes come from preexisting life.

What was the Golden Age of Microbiology?

1857-1914.

What major discoveries occurred during the Golden Age?

Germ theory, immunity, antimicrobials.

What is fermentation?

Conversion of sugar to alcohol by microbes.

What is pasteurization?

Brief heating to kill spoilage microbes.

Who proposed handwashing to prevent disease?

Ignaz Semmelweis.

Who introduced disinfectants in surgery?

Joseph Lister.

Who proved bacteria cause disease?

Robert Koch.

What are Koch's postulates used for?

Proving a microbe causes a disease.

Which Koch's postulate confirms causation?

Reproducing disease in a healthy host.

Who developed the first vaccine?

Edward Jenner.

What disease did the first vaccine prevent?

Smallpox.

What is chemotherapy?

Treatment of disease with chemicals.

What are antibiotics?

Microbial chemicals that inhibit or kill other microbes.

What enzyme do sulfonamides inhibit?

Dihydropteroate synthetase (DHPS).

Why don't sulfonamides harm humans?

Humans obtain folic acid from diet.

Who discovered penicillin?

Alexander Fleming.

What organism produces penicillin?

Penicillium fungus.

What is bacteriology?

Study of bacteria.

What is virology?

Study of viruses.

What is immunology?

Study of immunity.

What is recombinant DNA?

DNA from two different sources combined.

How is recombinant DNA used in medicine?

Produces insulin, vaccines, enzymes.

What is normal microbiota?

Microbes normally living in the body.

How does normal microbiota protect us?

Prevents pathogen growth.

What vitamins are produced by normal microbiota?

Vitamin K and folic acid.

What is a biofilm?

A complex aggregation of microbes on a surface.

Why are biofilms hard to eliminate?

They resist antibiotics and immune defenses.

What is an emerging infectious disease (EID)?

New or increasing disease.

What does MRSA stand for?

Methicillin-resistant Staphylococcus aureus.

Why is antibiotic resistance a major concern?

Treatment options become limited.

What causes West Nile encephalitis?

West Nile virus transmitted by mosquitoes.

What causes Ebola hemorrhagic fever?

Ebola virus.

What causes mad cow disease (BSE)?

Prions.

What disease is caused by E. coli O157:H7?

Severe diarrhea and hemorrhagic colitis.

What causes AIDS?

Human immunodeficiency virus (HIV).

Why is VRSA dangerous?

Few effective antibiotics remain.