Microbial metabolism is the means by which a microbe obtains the energy and nutrients (e.g. carbon) it needs to live and reproduce. Microbes use many different types of metabolic strategies and species can often be differentiated from each other based on metabolic characteristics.
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1 Synthesis of ATP at the expense of PMF formed by electron transport during aerobic or anaerobic respiration. [ 2 Note that in Oxidative phosphorylation chemical energy drives the redox reactions involved in electron transport; in Photophosphorylation light energy drives the electron transport reactions reactions.
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1 The reducing power is in the form of electrons carried in NADH and FADH, which are produced in the TCA cycle and passed to a membrane-bound electron transport system (ETS) terminated by oxygen (aerobic respiration) or another electron acceptor (anaerobic respiration). [ 2 See Question 9a.
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Anaerobic respiration: Some inorganic substance is final electron not oxygen. Example: In methanogens final electron acceptor is CO2 which combines with H+ to form methane. Fermentation: In fermentation there is no electron transport chain present energy is derived by converting glucose in lactic acid, ethanol etc.
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7) Define Respiration: Aerobic or anaerobic catabolic processes in which organic or inorganic electron donors are oxidized using oxygen (or an oxygen substitute) as the final electron acceptor. ATP is produced by oxidative phosphorylation.
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Although ferric iron is the most prevalent inorganic electron acceptor, a number of organisms (including the iron-reducing bacteria mentioned above) can use other inorganic ions in anaerobic respiration.
https://en.wikipedia.org/wiki/Microbial_metabolism
Denitrification is the utilization of nitrate (NO− 3) as a terminal electron acceptor. It is a widespread process that is used by many members of the Proteobacteria. Many facultative anaerobes use denitrification because nitrate, like oxygen, has a high reduction potential.
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While aerobic organisms during respiration use oxygen as a terminal electron acceptor, anaerobic organisms use other electron acceptors. These inorganic compounds have a lower reduction potential than oxygen, meaning that respiration is less efficient in these organisms and leads to slower growth rates than aerobes.
https://en.wikipedia.org/wiki/Microbial_metabolism
1 Note that electrons from the TCA cycle flow into the membrane and end up in the terminal electron acceptor. 2  This electron flow causes proton movement to the outside of the membrane leading to higher concentration of protons outside the cell, which causes a proton motive force (PMF) to form.
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Acetogenesis is a type of microbial metabolism that uses hydrogen (H 2) as an electron donor and carbon dioxide (CO 2) as an electron acceptor to produce acetate, the same electron donors and acceptors used in methanogenesis (see above).
https://en.wikipedia.org/wiki/Microbial_metabolism
in anaerobic respiration what serves as the final electron acceptor
In anaerobic respiration, oxygen or an oxygen substitute serves as the final electron acceptor. In anaerobic respiration oxygen serves as the final electron acceptor.