Ch.1 Humans and the Microbial World Flashcards
(26 cards)
Who was the scientist that was credited with viewing the 1st microorganisms?
Anthony Van Leeuwenhoek
- he called them animalcules
Spontaneous Generation
Belief that life arises spontaneously from non-living material
- early theory about life
Why is spontaneous generation not true?
- Louis Paster proved that air is filled with microorganisms which settled in bends of flask
- ended arguements that air or broths contained “vital force” necessary for spontaneous generation
- demonstrated that life cannot arise from non-living matter
Theory of biogenesis
describes the production of living things from other living things
- displayed in Pasteur’s results
normal microbiota
a populationof microrganisms carried in the human body
- prevents disease by competeing with diesase causing microbes and pathogens
- aids in digestion
- promote development of immune system
Food production using microrganisms
- baking bread using yeast
- fermintation of grains to produce beer
- fermentation of milk to produce yogurt, cheeses and buttermilk
Bioremediation
use of microrganisms to hasten decay of pollutants
prokaryotic cells
- do not have a membrane bound nucleus
- DNA in nucleoid region
eukaryotic cells
- have a membrane bound nucleus and organelles
- DNA protected by 2 membranes
Which domains are prokaryotes and eukaryotes?
- Bacteria = prokaryotes (no nucleus)
- Archaea = prokaryotes (no nucleus)
- Eukarya = eukaryotes (have nucleus)
Which domains have petidoglycan in their cell walls?
- Bacteria = has peptidoglycan in their cell wall
- Archaea = has no peptidoglycan in their cell walls
- Eukarya = has no peptidoglycan in their cell walls
Bionomial system on Nomenclature
Scientific names made up of two words
1. Genus = capitalized, italized and underlined
2. Species = not capitalized italized and underlined (may be abbreviated)
Viroid
- are considered non-living
- consist only of a single short piece of RNA
- obligate intracellular agents
- no protein coat
- cause a # of plant diseases
Prions
- are considered non-living
- misfolded versions of normal proteins that cause normal versions to misfold
- abnormal proteins form fibrils
- cells die leaving spaces in brain (spongiform encephalopathy)
Can viruses be active OUTSIDE of a host cell?
No, viruses are inactive outside host
- Viruses can only be active inside host
How can viruses be grown?
- infect living cells, reffered to as hosts
1. may kill host cell
2. may remain within host cell and replicate viral genetic info as host cell multiples
Do viruses have a nucleus?
no because they are considered non-living
- has DNA surrounded by protein coat
- nucleic acid pakckaged in protein coat
What does it mean to be an obligate Intracellular Parasite?
multiply using host cell machinery and nutrients
Which agents are considered obligate intracellular parasites?
- viruses and viroids
Shapes of Bacteria
- Coccus (plural: cocci)
- Bacillus (plural bacilli)
- Vibrio (plural: vibrios)
- Spirillum (plural: spirilla)
- Spirochete (plural: spirochetes)
- Pleomorphic
Coccus (plural: cocci)
Shape of Bacteria
Spherical cells, may be flattened
on one end or slightly oval
Bacillus (plural bacilli)
Shape of Bacteria
A rod shaped, cylindrical cell
Vibrio (plural: vibrios)
Shape of Bacteria
A short, curved rod
- boomerang shape
Spirillum (plural: spirilla)
Shape of Bacteria
A curved rod long enough to form spirals
- Ex: shape like a piece of hair
