BY 123L Taxonomy

What is a species?

group of organisms that are able to reproduce and produce viable offspring

What are the characteristics of Domain Archaea?

no peptidoglycan in cell walls, unique lipid construction in plasma membrane, some contain introns (non-coding parts of a gene)

What are methanogens?

type of archaea; live below mud in swamps, methane makers, reduce CO2 to methane, poisoned by oxygen (obligate anaerobe)

What are halophiles?

type of archaea; live in very salty places

What causes the color of halophiles?

a pigment called bacteriorhodopsin

What is the form of photophosphorylation in halophiles?

uses light but with carotenoids - so not called photosynthesis

What are thermoacidophiles?

type of archaea; live in areas with a pH of 2 and below and above 60C, can be found in deep sea vents or hot sulfur springs

What are endospores?

some bacteria that have cells able to withstand harsh environmental conditions

What is chemotaxis?

bacteria movement in response to a chemical gradients (+ or -)

What is phototaxis?

movement in response to light (+ or -)

What is flagella made of?

flagellin (protein)

What makes gram negative bacteria resistant to antibiotics?

has outer membrane, peptidoglycan, and a plasma membrane; gram positive does not have outer membrane

What are the 3 shapes of bacteria?

bacillus (rod), cocci (round), spirilla (corkscrew)

What are the 3 arrangements of bacteria?

diplo (paired), strepto (chained), staphylo (clusters)

What is the purpose of a capsule?

protective outer layer that protects against dehydration and host immune systems in bacteria

What is the purpose of pili?

projections attached to the outer layer; can be used for attachment or conjugation

What is binary fission?

how bacteria reproduces; produces clones

How do bacteria produce genetic variation?

mutations

What are plasmids?

self replicating circular chromosomes not associated with the bacteria’s normal chromosome; assists in horizontal gene transfer (genetic recombination)

What is conjugation?

transfer of DNA between two bacterial cells which are temporarily joined; DNA transferred through tube (pilus)

What is transformation?

process of taking in DNA from the external environment (usually DNA that has been shed by other bacteria)

What is transduction?

transfer of DNA between prokaryotes by viruses

What are bacteriophages?

viruses that infect bacteria

What is a photoautotroph’s energy source and carbon source?

light and carbon dioxide

What is a chemoautotroph’s energy source and carbon source?

inorganics and carbon dioxide

What is a photoheterotroph’s energy source and carbon source?

light and organic compounds

What is a chemoheterotroph’s energy source and carbon souce?

organic compounds for both

The majority of bacteria are..?

chemoheterotrophs; includes saprobes (feed on dead organisms) and parasites (feed on living hosts)

What is an obligate aerobe?

requires oxygen (most bacteria are this)

What is a facultative anaerobe?

can grow with or without oxygen; usually grows faster with it

What is an obligate anaerobe?

poisoned by oxygen; must have oxygen free environment

What is symbiosis?

an ecological relationship between different species which are in direct contact with each other

What is mutualism?

both species benefit

What is commenalism?

one benefits and the other is neither harmed or benefited

What is parasitism?

One benefits and one is harmed

What is ammensalism?

one does not benefit but the other is harmed

What is alpha proteobacteria?

many species in this subgroup are symbiotic with eukaryote hosts (mutualism)

What is beta proteobacteria?

nutritionally diverse, oxidizes ammonia to nitrites, mutualism

What is an example of beta proteobacteria?

neisseria gonorrhoeae - causes gonorrhea

What is gamma proteobacteria?

oxidizes hydrogen sulfide to sulfur

What are examples of gamma proteobacteria?

escherichia coli, vibrio cholerae (cholera), salmonella, and legionella (Legionnaire’s Disease)

What is delta proteobacteria?

slime producing myxobacteria

What is epsilon proteobacteria?

pathogens to humans and various animals

What are examples of epsilon proteobacteria?

helicobacter pylori (stomach ulcers) and campylobacter (blood poisoning and intestinal inflammation)

What are characteristics of kingdom chlamydia?

survives only in animal cells, steals ATP from inside animal cells (parasitism), odd cell wall that stains gram negative (has no peptidoglycan)

What is chlamydia trachomatis?

What are the characteristics of kingdom spirochetes?

uses flagella to “spiral” through an environment

What are the two types of bacteria in the kingdom spirochetes?

treponema pallidum (syphilis) and borrelia burgdorferi (lyme disease)

What are the characteristics of kingdom cyanobacteria?

photosynthetic, uses photosystem 1 and 2 and contains chlorophyll a, organisms arranged in filaments, some have heterocysts

What are heterocysts?

converts nitrogen to ammonia Anabaena

How does kingdom cyanobacteria photosynthesize?

no chloroplasts, chlorophyll found in thylakoid membranes scattered throughout the cell; uses photosystem 1 and 2 and contains chlorophyll a

What does the kingdom of gram positive bacteria contain?

two species of actinomycetes, streptomyces, bacillus anthracis, and clostridium botulinum

What are actinomycetes?

causes tuberculosis and leprosy, responsible for the “earthy” odor of rich soil, some are sources of antibiotics

What is streptomyces?

produces the antibiotic streptomycin that can destroy other bacteria

What is Bacillus anthracis?

produces anthrax

What is Clostridium botulinum?

botulism (paralysis, from contaminated food/water)

What is included in the kingdom gram positive bacteria?

mycoplasmas (only bacteria that does not have a cell wall)

What is disinfectant?

lyses most cells and used on non-living surfaces

What is antiseptic?

lyses some cells, prohibits growth and used on living tissue

What is the zone of inhibition?

clear spot around dot where bacteria has not grown (the bigger and clearer the area is, the more effective the antibiotic is)