Ch 11 Catabolism: Energy Release & Conservation Flashcards
Phototrophs
Organisms that use light as their energy source
Chemotrophs
Oxidation of chemical compounds as E source
Lithotrophs
Reduced inorganic subs as e- source
Organotrophs
Reduced organic compounds as e- source
Heterotrophs
Organisms that use organic molecules as source of C
Autotrophs
Organisms that use CO2 as source ( sole or principal) of C
Chemolithoautotrophs
Oxidize inorganic molecules w/ Fe, N or S for energy & e- for biosynthesis & use CO2 for C
Photolithoautotrophs
Aka photoautotrophs. Extract e- from inorganic molecules but gain E from light. CO2 is C source.
Chemoorganoheterotrophs
Aka chemoheterotrophs or chemoorganotrophs. Use reduced organic compounds of E, e- and C
Most human pathogens are
Chemoorganoheterotrophs
Photoorganoheterotrophs
Organisms that use light for E but organic matter for e- and C
Chemolithoheterotrophs
Use inorganic molecules for E and e-. Get C from organic sources.
Fueling reactions
Reactions that convert E, e-, & C sources ———> ATP, reducing power, & precursor metabolites
Reducing power
Molecules like NADH & NADPH that temp. store e-. Stored e- used in anabolic rxns (CO2 fixation & monomer synthesis)
Precursor metabolites
Intermediates of glycolytic pathways, TCA cycle and others that serve as starting molecules for biosynthetic pathways that gen monomers and other building blocks of macromolecules
How many types of general types of catabolic strategies?
2: respiration & fermentation
Respiration
E yielding process in which E substrate is oxidized using exogenous or externally derived e- acceptor. (NADH or FADH2 donates e- to ETC)
2 types of respiration
Aerobic respiration and fermentation (aka anaerobic respiration)
Terminal e- acceptor respiration
O2
Terminal e- acceptor fermentation
NO3- SO4-2 Fe+3
PMF
Proton motive force- a type of potential energy created during ETC, used to generate ATP
Endogenous acceptor
Acceptor from within the cell, usually an intermediate (eg pyruvate)
Aerobic respiration
Metabolic process in which organic molecules are oxidized w/ O2 as the final e- acceptor. Can completely reduce organic E source to CO2 using glycolytic pathways and TCA.
Aerobic respiration overview
Formation of pyruvate—> TCA cycle to oxidized pyruvate to CO2 ——> NADH & FADH2 from step 1&2 oxidized by ETC using O2 as final acceptor