Ch 1: The Microbial World and You Flashcards
Approximately what percent of microbes are pathogenic?
<1%
Intestinal microbes ferment food you can’t digest and produce some of the _______?
B and K vitamins
What species of fungus is responsible for the fermentation of soy sauce?
Aspergillus
Do transient microbiota cause disease? Why or why not?
No.
- unable to compete with residents
- Eliminated by body’s immune system
- Physical or chemical properties that discourage their growth (ex: temp, pH, etc)
By what ratio do microbes outnumber human cells in the body?
10:1
Under what conditions can our normal microbiota cause disease? (3)
- When they escape their normal habitat
- Immunosuppression
- Overgrowth (due to antibiotics)
Who established the system of scientific nomenclature for organisms?
Carolus Linnaeus (Swedish botanist and zoologist)
Theodor Escherich discovered what bacterium? What is its normal habitat?
Escherichia coli
Colon
Break down the name “Staphylococcus aureus”
Staphylo = clustered
Coccus = spherical cells
Aureus = gold-colored colonies
What is the most common way for bacteria to reproduce?
Binary fission
What is the primary component of bacterial cell walls?
Peptidoglycan
True or false. Archaea gain energy from organic and inorganic chemicals as well as photosynthesis.
False. They cannot phosynthesize
What is a halophile?
A microorganism that thrives in high salt concentrations
What are methanogens?
Archaeans that convert hydrogen to methane
What is the primary component of fungi cell walls?
Chitin
Molds and mushrooms are _____ while yeasts are _____
Molds/mushrooms: multicellular
Yeasts: unicellular
Are most fungi molds or yeasts?
Molds
~1% are yeasts
Do protozoans reproduce sexually or asexually?
Either
Are protozoans prokaryotes or eukaryotes?
Eukaryotes
What is the primary component of cell walls in algae?
Cellulose
Who is credited with inventing the first compound microscope in 1595? What was its magnification?
Zacharias Jansen and Hans Lipperhey
3-9x magnification
Robert Hooke’s observation of cork under a primitive compound microscope led to the ________.
Cell theory
1673-1723: _____ was the first person to visualize live microorganisms. He is known as the “father of microbiology”
Anton van Leeuwenhoek
What was the magnification of Leeuwenhoek’s simple microscope?
x300
Describe the “spontaneous generation” theory
Prior to the 1850s, many scientists and philosophers hypothesized that some living organisms could arise from nonliving matter; a “vital force” forms life
(i.e. maggots from decaying corpses, flies from manure)
In 1668, ______ performed the decaying meat experiment to test the spontaneous generation of maggots?
Francesco Redi
In 1861, _____ finally disproved the spontaneous generation theory by designing a flask to let air in but keep microbes out
Louis Pasteur
Describe Pasteurization
Application of heat for a short time to kill pathogens and reduce the number of spoilage bacteria.