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What are the 3 common shapes of prokaryotes?
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what shape does cocci mean?
Spheres
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what shape does bacilli mean?
Rods/cylindrical
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what shape does Spirilla mean?
spirals
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What are plasmids?
contain genes with functions that supplement those in nucleoid
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what is the internal structure of prokaryotes?
- small circles of DNA called plasmids
- Ribosomes that are smaller than eukaroytes
- and have fewer protiens and RNA molecules
- Cytoplasm
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what does prokayotes cytoplasm made of?
- granules of:
- glycogen
- lipids
- phosphates
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What is the primary structural molecule of bacteria cell wall?
Peptiodoglycan
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what is peptidoglycan?
a polymer formed from a polysaccharide backbone with polypeptides
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What are the steps of the Gram stain technique?
- Treat bacteria with crystal violet dye, then iodine
- bacteria then washed with ethanol, then with fushin or sfranin
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If a bacteria tests gram positive it means?
the cell wall consists of a thick peptide layer and will be stained purple
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If a bacteria is Gram negative it means?
that the cell has a thin peptide layer and will be stained pink
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Concerning prokaryotic cell walls, the outermembrane covers what layer?
peptidoglycan layer
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What consists of the outer membrane? What does it do?
- consists of lipopolysaccharides
- and protects Gram Negative bacteria
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walls of Gram positive and Gram negative bacteria are coated with an external layer of...?
Glycocalyx
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what is Glycocolyx?
- 2 forms
- The "slime layer" when it's diffuse and lossely associated with the cells
"Capsule" when it's gelatinous and more firmly attached to the cells
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What is the most common mechanism for movement in bacteria and archaens to allow them to move through liquids and wet surfaces?
Flagella
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What aspect of the flagella differs from tht of eykaryotes and prokaryotes
- Eukaryotes have micotubles in flagella
- Prokaryotes have no micotubles
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What is Pili? What is it used for?
- Rigid, hairlike shfts of a
- protein = pili
Maybe be used for sexual reproduction I.E. genetic transfer
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Do Prokaryotes have the greatest metabolic diversity of all living organisms?
yes
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What is an Autotroph?
- auto=self
- troph=nourishment
Obtain carbon from CO 2 (inorganic molecules)
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What is a Heterotroph?
Obtain carbon from organic molecules of living hosts, or from products, wastes, or dead organisms
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What is a Chemoautotroph?
- Obtain energy from inorgainc substances
- ex. H, Fe, S, Nitrites
- Obtain carbon from CO2
- Use e- they remove in oxidations to make organic molecules by reducing CO2 or provide energy for ATP synthesis
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What are Chemoheterotrophs?
- Oxidize organic molecules as their energy source
- Obtain carbon in organic form
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What are Photoautotrophs?
- Photosynthetic (light as energy source)
- Carbon from CO2
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What are Photoheterotrophs?
- Use light as ultimate energy source
- Obtain carbon in organic form other then CO2
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What are Aerobes?
Require oxygen for cellular respiration (oxygen is final electron acceptor)
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What is an obligate aerobe?
Cannot grow without oxygen
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What is an anarobe?
Do not require oxygen to live
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What is an obligate anarobe?
- Poisoned by oxygen
- survive by fermenting in which organic molecules are final e- acceptor
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What are facultive anarobes?
- Use oxygen when it's present
- Under anaerobic conditions they live by fermentation
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What is Nitrogen fixation?
- Process in which atmospheric nitrogen to ammonia (NH3 )
- Only process for replenishing nitrogen sources used by plants and animals
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What is Nitrification?
The conversion of ammonium (NH 4 +) to nitrite(NO 2 -) which is carried out in 2 steps
- 1 type converts ammoium to nitrite
- Other type converts nitrite to nitrate
- Both are usually present in soils and water
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What is the normal mode of reproduction in prokaryotes?
Asexual reproduction
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What is binary fission?
during asexual reproduction the parent cell divides into 2 daughter cells that are exact genetic copies of the parent
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What is conjugation?
during sexual reproduction, exchange genetic material when 2 parent cells join or mate
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What does Biofilm consist of?
A complex aggregation of microorganisms attached to a surace
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What are the 5 major evolutionary groups of Bacteria?
- Proteobacteria
- Spirochetes
- Chlamydias
- Gram-positive bacteria
- Cyanobacteria
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Name some features of Proteobacteria
- Highly diverse group
- largest of all groups
- ex. myxobacteria which has a fruiting body
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Name some features of Spirochetes
- Gram negative bacteria
- Helically or spiralled bodies
- linear chromosomes
- ex. treponema pallidum which causes syphilis
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Name some features of Chlamydias
- Gram-Negative bacteria
- Have cell walls with a membrane outside of them
- Are Obligate intracellular parasites=only reproduce within other cells
- Causes various diseases within animals
- Ex. trachomatis = urinary tract infection
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Name some features of Gram-Positive Bacteria
- Gram Positive
- live primarily as chemoheterotrophs
- Thick cell walls
- Some are beneficial to humans
- ex. lactobacillus cary out lactic acid fermentation used in production of pickles
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Name some features of Cyanobacteria
- Gram-Negative
- Live and photoautotrophs
- Have chlorophyll = their pigment
- use same pathway for phtosynthetic plants and algae
- Release oxygen as a byproduct of photosynthesis
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What are exotoxins?
Toxic proteins that are secreted from the bacterium
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what are endotoxins?
Toxic protenins secreted from bacteria after they have died
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What are Exoenzymes?
Enzymatic proteins that digest plasma membranes and cause cells of infected host to rupture and die
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Name some basic features of the domain Archaea
- Found in estrmem environments such as hot springs, thermal vents, and salt lakes
- many are chemoautotrophs
- many are chemoheterotrophs
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What are the 3 evolutionary branches in the archaea
- Euryarchaeota
- Crenarchaeota
- Korarchaeota
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What are the 3 found in Euryarchaeota
- Methanogens
- Extreme Halophiles
- Some extreme thermophiles
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List some characteristics of Methanogens
- Represent about half of all known species of Archaens
- obligate anaerobes
- live in reducing environment
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List some characterisitcs of Halophiles
- Salt loving
- All belong to Euryarchaeota
- need min. conctration of 1.5M NaCl to live
- aerobic chemoheterotrophs
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List some characteristics of Extreme thermophiles
Need environment of 70-95 Celsius for maximum growth
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List features of Crenarchaeota
- Contains most of the extreme thermophiles
- temp range 75-105
- Psychrophiles = cold loving
- grow optimally in range of -10 to -20
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List some things about Korchaeota
- recognized by analyzing rRNA sequences in DNA from marine and terrestrial environments= hydrothermal
- Oldest lineage in domain Archaea
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