Microbiology 204; Waldmann: Exam 2 – Flashcards
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| biological species |
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| a group of inter-breeding organisms |
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| bacterial strain |
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| a group of genetically-identical bacteria |
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| bacterial species |
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| a group of very similar strains that differ significantly from other strains; a group of bacteria that share 70% or more biochemical similarity |
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| genus |
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| a group of closely-related species (taxonomy term) |
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| kingdom |
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| the highest classification rank used in traditional classification (up to the mid-70s); a group of closely-related phyla |
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| domain |
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| the highest classification rank used in modern taxonomy since the mid-70s; a group of closely-related phyla |
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| spirilla |
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| coiled bacteria |
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| spirochetes |
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| unusual spiral-shaped bacteria that have a sheath surrounding the cell |
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| cocci |
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| spherical bacterial |
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| vibrio |
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| comma-shaped bacteria |
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| bacilli |
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| rod-shaped bacteria |
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| streptobacilli |
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| rod-shaped bacteria in chains |
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| streptococci |
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spherical bacteria in chains
[image] |
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| staphylococci |
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| spherical bacteria in clusters |
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| diplococci |
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| spherical bacteria in pairs |
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| coccobacilli |
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| very short rods or slightly elongated round bacteria |
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| genome |
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| all of the genetic material in a virus, cell, or organism |
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| lipopolysaccharides |
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| molecules found in the outer membrane of Gr- bacteria; can be toxic to humans |
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| cell membrane (aka plasma membrane) |
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| a thin layer surrounding the cytoplasm in cells |
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| cell wall |
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a layer immediately outside the cell membrane function: supports the cell membrane (prevents cell lysis); determines the Gr rxn of the cell; anchors teichoid acids in Gr+ bacteria; many layers thick in Gr+ bacteria but only 1-3 layers thick in Gr- cells |
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| outer membrane |
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a [typically ruffled] layer outside the cell membrane and the cell wall; found only on prokaryotes; found mainly on Gr- bacteria function: holds secreted materials in the periplasm; protects cell by preventing the penetration of some chemicals (i.e. antibiotics) |
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| periplasm or periplasmic space |
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the space between the outer membrane and the cell membrane; found only on prokaryotes; found mainly on Gr- bacteria function: contains enzymes & other material that protect & nourish the cell by breaking down entering compounds |
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| glycocalyx |
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| a layer coating the cell (found outside all other layers) function: attachment, protection against dehydration & phagocytes; can create a biofilm |
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| slime layer |
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| thin & flexible glycocalyx |
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| capsule |
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| thick & rigid glycocalyx |
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| biofilm |
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| a community of microbes attached to a surface; can be caused by glycocalyx or by pilus |
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| pilus |
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| a thin, relatively short, hair-like projection from a prokaryotic cell; can create a biofilm |
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| inclusion body |
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| granules (larger than ribosomes) visible in prokaryotic cells function: store excess nutrients or energy |
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| plasmid |
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| a small accessory DNA molecule in P&E cells; looks like a chromosome, only smaller; rare & linear in eukaryotic cells; common & looped in prokaryotic cells |
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| lysozyme |
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| an enzyme made by many organisms to break bonds in peptidoglycan |
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| penicillin |
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| a compound produced by fungi in the genus Penicillium to prevent the formation of peptide cross-bridges in peptidoglycan |
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| peptidoglycan |
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| the compound used by bacteria to make cell walls |
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| endospore |
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| a structure that stores a copy of the bacterial chromosome during periods of harsh conditions; formed by some Gr+ bacteria |
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| vegetative cell |
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| an actively-growing plant or bacterial cell |
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| germination |
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| the first of two stages of the process of forming a vegetative cell from an endospore |
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| sporogenesis (aka sporulation) |
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| the process in which a vegetative cell forms an endospore |
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| binary fission |
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| a process of splitting in two; in micro, it is the process in which a prokaryotic cell splits to form two daughter cells |
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| doubling time (aka generation time) |
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| the time it takes for a prokaryotic cell to complete the cycle of cell reproduction |
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| lag phase |
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| the first phase in the plot of the growth of a culture |
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| lag phase |
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| the phase in the plot of the growth of a culture when bacteria are put in a new culture and they do not grow immediately |
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| log growth phase |
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| the second phase in most plots of culture growth; cells are growing rapidly and constantly in this phase |
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| stationary phase |
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| the third phase in most plots of culture growth; the phase in which cell number does not change because cell divisions are balanced by cell deaths |
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| log death phase |
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| the fourth and last phase in culture growth plots; the decline phase; the phase in which cells die logarithmically |
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| log growth phase |
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| the phase in plots of culture growth in which cell number increases logarithmically as doubling time remains constant |
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| log growth phase |
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| the phase in plots of culture growth which ends when nutrients become scarce or when waste products become concentrated and inhibit growth |
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| log death phase |
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| the phase in plots of culture growth which occurs when nutrients are extremely scarce and/or waste products are very concentrated |
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| late log growth, when nutrients are running out; process should be completed by log death phase |
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| the phase of culture growth in which cells that can make endospores would begin sporogenesis |
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| late log growth |
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| the phase of culture growth in which cells that can make antibiotics begin to make them |
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| stationary phase |
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| the phase of culture growth in which antibiotic production is normally most robust |
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| log growth phase |
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| the phase of culture growth in which symptoms arise after a pathogen has entered a host; symptoms occur because the bacteria are releasing waste products that are toxic to the host or because the growing cells damage host tissue |
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| thermophile |
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| an organism or species whose optimal growth rate is at elevated temperatures (between 45 and 70ºC) |
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| mesophile |
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| an organism or species whose optimal growth rate is at moderate temperatures (between 15 and 45ºC) |
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| psychrophile |
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| an organism or species whose optimal growth rate is at low temperatures (below 15ºC) |
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| strict aerobe (aka obligate aerobe) |
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| an organism that must have oxygen in order to survive and reproduce |
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| strict anaerobe (aka obligate anaerobe) |
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| an organism that dies when exposed to oxygen: it survives and reproduces in environments lacking oxygen |
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| facultative |
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| an organism that grows well with or without oxygen |
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| anaerobe |
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| an organism that does not use oxygen (and prefers environments with no or low oxygen) |
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| microaerophile |
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| an organism that grows fastest in an environment with a low level of oxygen |
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| aerotolerant |
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| an anaerobe that is not harmed by oxygen |
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| capnophile |
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| an organism that requires comparatively high CO2 and (often) comparatively low O2 |
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| neutrophile |
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| an organism that grows fastest in an environment that has a pH near 7 |
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| acidophile |
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| an organism that grows fastest in an environment that has a pH below 7 |
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| basophile |
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| an organism that grows fastest in an environment that has a pH above 7 |
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| chemical reaction |
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| a process in which some compounds (reactants or substrates) are converted to new compounds (products) |
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| chemical reaction |
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| a process in which chemical bonds change |
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| metabolism |
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| the set of chemical & physical processes involved in the maintenance of life |
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| anabolism |
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| the energy-consuming process of incorporating nutrients into protoplasm through biosynthesis |
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| catabolism |
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| the chemical breakdown of complex compounds into simpler units to be used in cell metabolism; |
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| catabolism |
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| reactions in which molecules are broken down, releasing energy & subunits |
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| metabolic pathway |
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| a series of cellular reactions in which a product of one reaction is a reactant in the next reaction |
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| catalyst |
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| something that speeds up the rate of a reaction but is not permanently changed by the reaction; most are enzymes; a few are ribozymes |
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| substrate |
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| a reactant in an enzyme-catalyzed reaction |
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| ribozyme |
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| a biological catalyst composed primarily of RNA |
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| enzyme |
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| a biological catalyst composed primarily of protein |
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| cofactor |
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| any nonprotein component (helper) of an enzyme |
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| coenzyme |
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| an organic compound that works with an enzyme (often a vitamin) |
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| reduction |
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| the addition of electrons |
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| oxidation |
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| the removal of electrons |
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| NAD+ and FAD |
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| the electron carriers most commonly used in catabolic reactions |
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| fermentation |
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| the partial oxidation of a nutrient using internal, organic compounds as the final electron acceptor |
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| organic compounds |
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| carbon-based compounds that contain C-C and/or C-H bonds |
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| partial oxidation |
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| not all of the electrons that can be removed from the nutrient are removed (all the energy is not harvested) |
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| aerobic respiration |
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| the complete oxidation of a nutrient using O2 |
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| CO2 (carbon dioxide) |
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| the completely oxidized form of carbon |
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| anaerobic respiration |
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| the complete oxidation of a nutrient using an external final electron other than O2 |
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| phosphorylation |
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| the bonding (adding) of a phosphate group to a molecule |
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| common products of fermentative reactions |
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| cytochromes |
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| electron carriers in the electron transport system |
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| cytochrome oxidase |
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| the electron carrier that passes the electrons to O2 |
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| Proton Motive Force (PMF) |
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| the energy of the transmembrane proton gradient (an electrochemical gradient similar to a battery) |
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| chemiosmosis |
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| a process in which protons are allowed to flow down an electrochemical gradient and the energy released as they flow down the gradient is used to drive an energy-requiring process, such as the phosphorylation of ADP to form ATP |
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| beta oxidation |
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| a metabolic pathway that oxidizes fatty acids, producing NADH & acetyl-CoA |
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| phototroph |
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| an organism that gets energy from light |
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| chemotroph |
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| an organism that gets energy from chemicals |
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| heterotroph |
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| an organism that gets carbon from organic sources, i.e., carbon-based compounds produced by other living organisms |
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| autotroph |
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| an organism that gets carbon from inorganic sources, typically CO2 |
