Exam 1 Flashcards
Describe a virus
not a cell
cannot change or replicate without a host cell
contains nucleic acids (RNA/DNA) in a protein coat (capsid)
Describe bacteria
usually no internal membranes
nucleoid region with a single DNA molecule
one chromosome
Describe Archaea
Usually no internal membrane
nucleoid region with a single DNA molecule (one chromosome)
Describe Eukarya
Examples: Fungi, Protists, Algae
membrane enclosed nucleus with several DNA molecules (multiple chromosomes)
membrane-enclosed internal structures (mitochondria, chloroplasts)
Medical microbiology
pathogenic, virology, immunology
Environmental microbiology
ecology, bioremediation, wastewater and sewage treatment
Industrial microbiology
food (vinegar, cheese, yogurt, high fructose corn syrup)
fermentations (yeast - saccharomyces cerevisiae)
Agricultural microbiology
nitrogen fixation in legumes (Rhizobium)
rumen in cows, biological pest control
(Bacillus thuringiensis)
Biotechnology/genetic engineering
insert human genes into bacteria
ex: most insulin is now produced by microorganisms
What are the 5 kingdoms?
Plants
Animals
Fungi
Protists
Monera
How are species named?
Binomial naming structure
first part = genus
second part = species
What are the 3 domains?
Bacteria
Archaea
Eukarya
What is the order of the taxonomic scale?
(Domain)
Kingdom
Phylum
Class
Order
Family
Genus
Species
Are archaea more similar to bacteria or eukarya?
Archaea are more similar to eukarya at a cellular and genetic level
What is the difference between Heterotrophs and Autotrophs?
Heterotrophs = reduced, pre-formed, organic molecules from other organisms
Example: humans eat food to obtain energy
Autotrophs = CO2 or other principle biosynthetic carbon sources
Example: plants
What is the difference between chemoautotrophs and photoautotrophs?
Chemoautotrophs → energy source = oxidation of inorganic/organic chemicals
Example: nitrogen fixing bacteria/ bacteria oxidizing H2S, ammonia, methane, etc
Photoautotrophs → energy source = light
Example: plants use sunlight for carbon fixation (photosynthesis)
light-induced electron flow creates ATP by proton gradient and membrane ATPase
What is the difference between aerobes and anaerobes?
Aerobes - metabolism requires the presence of oxygen
Anaerobes - metabolism does not require the presence of oxygen
What is the difference between acidophiles and alkalophiles?
Acidophiles - prefer acidic conditions - pH below 7
Alkalophiles - prefer basic conditions- pH above 7
What is the difference between thermophiles and psychrophiles?
Thermophiles - high temperature optima
Hyperthermophiles - very high temperature optima - Found in unusually hot environments - Hot springs and deep sea thermal vents
Psychrophiles - low temperature optima
Found in unusually cold environments
Mesophiles - midrange temperature optima
Widespread in nature and most commonly studied microorganism
How many bacteria can be found per square inch of soil or drop of water?
Over a million
Do you have more bacterial cells or body cells?
More bacterial cells in your body than cells of your body
How does the total surface area of bacteria compare to the surface area of the Earth?
Total surface area of bacteria on Earth more than 4X surface area of Earth
What limits the distribution growth of microorganisms?
Probably only thing limiting distribution growth of microorganisms is water
What do microbial cells do?
- Metabolism: consume nutrient source for energy
- Grow and replicate: create new cell material to produce new cells
- Differentiate: form specialized cell structures/cell types for specific purposes
- Respond to signals: movement, cell-cell signaling
- Change genetically: vertical and horizontal gene transfer
What made Antonie van Leeuwenhoek famous?
1684 - discovered “animalcules”
When was the “Golden age of microbiology”?
1850-1930
What made Beadle and Tatum famous?
1941 - one gene- one enzyme hypothesis
What made Watson and Crick famous?
1953 - double helix structure of DNA
What made Carl Woese famous?
1977 - used rRNA to form the Three Domain hypothesis
What made Craig Venter famous?
1995 - completed first complete genome sequence of an organism
Haemophilus influenzae
What made Ferdinand Cohn famous?
- German Botanist in mid 1800’s
- First to classify algae as plants, regarded bacteria as members of plant kingdom
- Classified bacteria based on their shape
- Studied Bacillus and discovered they can form heat-resistant cell structures (endospores)
What made Louis Pasteur famous?
- French chemist in the late 1800’s
- Refuted the spontaneous generation of germ theory
- Showed that fermentation is caused by microorganisms and that heating liquids can stop this (led to pasteurization)
- Pioneered ideas of vaccination and immunity
developed first vaccine for rabies
What made Robert Koch famous?
- German physician in late 1800’s
- First to isolate Bacillus anthracis and Mycobacterium tuberculosis
- First to link a specific bacterium (B. anthracis) to a specific disease (anthrax), and
developed “Koch’s Postulates” as criteria for this
What are the Koch’s Postulates?
- The specific bacterium must be present in diseased animals and not in
healthy animals - The bacterium must be isolated and obtained in pure culture
- The pure culture is used to inoculate a healthy animal, and this animal must
become sick with the disease - The same bacterium is isolated again from the new infected animal
What made Paul Ehrlich famous?
- German scientist in early 1900’s
- Developed first antimicrobial chemical (Salvarsan) to treat syphilis
- Developed the idea of chemotherapy
Alexander Fleming - Scottish pharmacologist in early 1900’s
- Discovered the first antibiotic (penicillin) in 1928 when he noticed mold
contaminating plates of Staphylococcus, which seemed to kill the bacteria - Discovery ignored until large scale production of penicillin in the 1940’s
What was the first antibiotic ever discovered?
penicillin
What was the first disease discovered to be caused by a bacertium?
Anthrax