Biology 109: Chapter 27
48 Cards in this Set
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Prokaryotes
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_____________ are found in extreme habitats of temp, salinity, and pH.Combined mass in the biosphere is 10X> than all eukaryotes combined.
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symbiotic
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Prokaryotes also live in ___________ relationships with other prokaryotes and eukaryotes.
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Bacteria; Archaea
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Prokaryotes have two main branches of evolution including __________ and __________.
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Cocci
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______ are spherical in shape
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Bacilli
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_______ are rods in shape
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Spirilla, spirochetes
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____________ are helical in shape
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cell wall
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Nearly all prokaryotes have a _____ _____ external to the plasma membrane.
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cell wall
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The ______ _____ maintains cell shape, affords physical protection, prevents bursting in hypotonic environment (will plasmolyze in hypertonic environment).
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Peptidoglycan
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_____________ is made up of sugars that are cross-linked with polypeptides.
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Archaen
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_________ cell walls contain polysaccharides and proteins but lack peptidoglycan.
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negative
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Gram __________ are more threatening because they have possible toxic lipopolysaccharides, outer membranes that protect against host defenses, and a greater resistance to antitiobics.
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Penicillin
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__________ is an abx that inhibits cross-link formation and interferes with cell wall function
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Capsule
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Prokaryotes secrete a sticky substance called a ________ that forms another protective layer. It also enables prokaryotes to adhere to their substrate or to other idividuals to form a colony and shield pathogenic species from host's immune system.
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Fimbriae
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_________ are hair-like appendages and are also known as attachment pili.
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Taxis
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______ is directional movement. Chemotaxis and phototaxis are different types.
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Plasmid
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smaller rings of DNA that are needed for special contingencies, replicate independently, and can be transferred between partners.
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binary fission
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Prokaryotes reproduce asexually by ________ _________. No mitosis or meiosis.
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Horizontal Gene Transfer
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Bringing together DNA from different individuals and facilitates rapid evolution.
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Mutation
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_________ is a major source of genetic variation
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transformation; conjugation; transduction
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Prokaryotes have three mechanisms that can function to transfer genes between individuals and they are __________, __________, and _________.
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Transformation
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cell that takes up genes from surrounding environment
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Conjugation
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direct transfer of genes from one prokaryote to another
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transduction
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viruses transfer genes from one prokaryote to another.
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Endospores
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Prokaryotes can withstand harsh conditions and some form resistant cells that are called ___________, when essential nutrient in environment is lacking. They can withstand boiling water and can remain dormant for centuries.
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Phototroph
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use light energy
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chemotroph
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energy from chemicals in environment
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autotroph
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need only C02 (inorganic)
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hetertroph
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require at least one organic nutrient.
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Photoautotrophs
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Photosynthetic organisms use light energy to drive synthesis of organic compounds from CO2 (plants and algae)
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Chemoautotrophs
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Need only CO2, but oxidize inorganic substances for energy (H2S, NH3, FE2+)
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Photoheterotrophs
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Use light for energy, obtain carbon in organic form
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Chemoheterotrophs
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Consume organic molecules for energy and carbon (protists, fungi and animals and some parasitic plants)
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Denitrify
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Soil nitrite (NO2-) and nitrate(NO3-) return N2 to atmostphere
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Nitrogen fixation
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Convert N2 to NH4+. Only biomechanism that makes atmospheric N2 available to organisms.
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Proteobacteria, clamydias, spirochetes, gram+ bacteria, cyanobacteria
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The most known prokaryotes are bacteria and the 5 major clades are _____________, __________, ____________, _________________, and _______________.
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Proteobacteria
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Gram- bacteria
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Clamydias
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urethritis- most common STD in US
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Spirochetes
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syphillis, Lyme disease
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Gram+ bacteria
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ACtinomycetes - tubercolosis, leprosy, streptomyces - abx (streptomycin), spore formers such as Baccilus anthracis and Clostridium botulinum
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Cyanobacteria
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only prokaryotes with plantlike oxygenic photosynthesis
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Euryarchaeota, crenarchaeota, korarchaeota, nanoarcheota
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The four major taxa of Archae are ___________, ___________, ___________, and ___________.
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Extreme thermophiles
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Live in extreme hot temperatures
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Extreme halophiles
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Live in high-salt environments
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methanogens
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obtain energy by using CO2 to oxidize H2 --> CH4 strict anaerobes, poisoned by O2.
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Symbiosis
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An ecological relationship between organisms of different species that are in direct contact
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Mutualism
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both benefit
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Commensalism
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one receives benefits while neither harming nor helping the other
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parasitism
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one (parasites) benefits at expense of host
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Biology 109: Chapter 27