chapter 16 (test 1) Flashcards
What are the 3 domains
Bacteria, archaea, eukarya
central apparatus of gene expression of bacteria
-RNA polymerase
-ribosomal RNAs
-translation factors
bacteria cells walls are made of…
peptidoglycan- target for antibiotics
gram-positive bacteria
stephylococcus, streptococcus and some bacillus. this cell wall with no outer membrane
listeria
gram+, polymerizes actin inside host cells
lactobacillales
key genera: Lactobacillus, streptococcus
fermentative bacteria, produce lactic acid
energy from substrate-level phosph
aerotolerant anaerobes
Lactobacillales- no sensitive to oxygen
Streptococcus
Gram +
Leuconostoc
Gram positive, makes sauerkraut
Nonsporulating bacillales and clostridiales
Key genera: listeria, stephylococcus, carcina
Listeria
order bacillales, found in soils, opportunistic Pathogen that causes foodborne illness gram+, Facultatively aerobic chemoorganotrophs, grow at low temps
stephylococcus
Facultative aerobe that respires, catalase-positive, resistant to reduced water potential and tolerate drying and high salt, gram +, aureus, parasites of humans and animals
sporulating bacillales and clostridiales
Key genera: Bacillus, clostridium, sporosarcina, all endospore-forming bacteria
Gram-positive endospores
extremely heat-resistant for millennia, toxin formers
Clostridium
Gram+ endospores, Tetanus, Botox, gangrene, Oxygen kills, lacks respiration chain and obtains ATP by substrate-level phosphorylation.
Bacillus
anthrax (kills cells), spore forms inside mother cell
Bacullus and paenibacillus
secretes exoenzymes- hydrolytic enzymes that break down polymers, produce antibiotics
Tenericutes
Key Genera: Mycoplasma, spiroplasma, lack cell walls and peptidoglycan, some of the smallest orgs, related to firmicutes, small genomes
Mycoplasmas
small, pleomorphic cells, show “fried egg” appearance in colonies
Actinobacteria
Coryneform and propionic acid bacteria, Key genera: Anthrobacter, Corynebacterium (throat), mostly harmless with exception of mycobacterium
Gram positive actinobacteria
Acid fast cell walls, waxy lipids in cell wall, streptomyces-source of many antibiotics
Gram-negative proteobacteria
largest group with 6 major classes, many metabolic abilities: purple light receptors, use of inorganic, electron donors, highly adaptable metabolism,
Alpha proteobacteria
Photoheterotrophs-Rhodospirillum
endosymbionts
Rhizobium, Agrobacterium- plant tumors
Rickettsias- close relation to human mitochondria, parasites cause rocky mountain spotted fever
Beta proteobacteria
Lithotrophs, iron, nitrate, sulfur oxidizers
Nitrosomonas used in wastewater treatment
Pathogens- Neisseria Gonorrhoeae- diplococcus
Gamma proteobacteria
lithotrophs, some are phototrophs, purple sulfur bacteria
chromatium- deposits sulfur inside cell
thiocapsa- uses nitrate as electron donor
Enteric Gamma proteobacteria
in the Gut,
facultatively anaerobic rods- escherichia coli, pathogens causing salmonella, proteus, shigella
Aerobic rods- some in biofilms, some pathogens, pseudomonas
Delta proteobacteria
Myxococcus xanthus- attacks other bacteria
Bdellovibrio bacteriovorus- parasitizes other bacteria and lyses host (attacks e-coli)
Epsilon proteobacteria
smallest group of proteobacteria
helicobacter pylori-causes stomach ulcers
urinase-base to protect from acidity of stomach
Nitrospirae
spiral shape, most oxidize nitrite to nitrate, nitrospira
leptospirillum- oxidizes iron, fixes carbon
Bacteroidetes and chlorobi
obligate anaerobes, bacteroides- break down toxins in food
chlorobium- green sulfur bacterium
spirochetes
Own genetic phenotype, flexible, narrow spiral shape with flagella at ends, form axial filament
chlamydiae
Obligate intracellular parasites-leading sexually transmitted
small elementary bodies grow into larger reticulate body that does not survive outside of host
planctomycetes
Multiple internal membranes, double membrane around nucleoid
verrucomicrobia- irregular shape contains tubulin
tubulin
arms used for attachment
Cyanobacteria
oxygenic phototrophs
thylakoids (membrane)- site of photosynthesis, similar to chloroplasts
carboxysomes- lipid bodies, gas vesicles
can secrete protective mucilage
many form akinetes- specialized spore cells used to spread
deep-branching thermophiles
chloroflexi- green nonsulfur bacteria, filamentous phototrophs, live at high temps (yellowstone)
many have chlorosomes- membrane bound organelles that contain chlorophyll
Deinococcus- Thermus
aerobic chemoorganotrophs, stain Gram+ but have Gram- wall containing several layers but lacking lipid A and containing ornithine
thermales- thermus aquaticus a model for life at high temps and is source of taq DNA polymerase
deinococcus radiodurans
radiation resistant, most are red or pink
