Microorganisms Notes – Part I
Bacteria
Prokaryotes – single-celled organisms that lack a ______
Separated into two kingdoms:
Archaebacteria – lack peptidoglycan in cell wall, DNA more similar to eukaryotes than eubacteria
- also known as “______”
Ex: methanogen (oxygen free, make ______), halophiles (love salt)
Eubacteria – surrounded by cell wall what has peptidoglycan (a ______)
Ex: ______ (see below)
Identifying Prokaryotes
Shape
Rod shaped –
Spherical –
Spiral –
Cell Walls
Presence and amount of ______
Movement
If they move:
- ______(above)
- ______
- secreted ______
- other projections
Releasing Energy – need a constant supply of energy (whether from ______)
- obligate aerobes – need ______
- obligate ______– cannot have oxygen
- facultative anaerobes – can live with or without ______
- can switch from using cellular respiration (use ______) to fermentation (without oxygen)
Growth and Reproduction
Binary Fission – ______reproduction
- undergoes ______, makes 2 daughter cells with identical DNA
- does not increase ______
Conjugation – not really reproduction
- transfer of ______between two cells
- ______biodiversity
Spore Formation – keeps bacteria safe in ______conditions
Importance of Bacteria
Decomposers – recycle nutrients from ______organisms
Nitrogen Fixers – convert nitrogen into a form ______can use
Human uses – produce foods and beverages, clean up wastes, and found in our bodies
Ex: E. coli – found in our ______, help absorb ______
- certain strains, like O157:H7 can be toxigenic (produce ______)
- thrive in intestines of grain-fed cattle and removed by ______
- when cows are slaughtered, some feces may mix with ______
- unlike many strains, this strain is resistant to our ______
Antibiotics – used to kill bacterial infections (like those caused by bad E. coli)
- antibiotic resistance – bacteria may be resistant to antibiotics
- ______allow antibiotic resistant bacteria to survive, thrive, and reproduce
- reasons for antibiotic resistance:
1) overuse of antibiotics in humans
- ______
- ______
- anti-bacterial ______gets in water, water is treated, but ______properties remain in water when it returns to human and animal use
2) use of antibiotics as ______promoters in food animals