Summary
Bacteria use alternative terminal acceptors such as nitrate or sulfate in the electron transport chain.
In depth
Alternative acceptors: nitrate (denitrifiers), sulfate (sulfate reducers producing H2S), CO2 (methanogens), Fe3+ (Geobacter). Yield less energy than oxygen. Important in global cycles.
Anaerobic respiration uses an electron transport chain with acceptors other than oxygen. It is crucial in sediments and guts. Sulfate reducers produce H2S.
Key idea: it differs from fermentation because it uses an ETC.
Some bacteria and archaea respire without oxygen by using another inorganic molecule as the final electron acceptor in an electron transport chain, producing ATP via a proton gradient. Examples are nitrate (denitrifying bacteria giving N2), sulfate (Desulfovibrio giving hydrogen sulfide), ferric iron, and CO2 (methanogens, producing methane).
The ATP yield is less than aerobic but more than fermentation. These organisms are important in the nitrogen and sulfur cycles, in waterlogged soils, marine sediments, the digestive tracts of ruminants and wastewater treatment. Denitrification can cause loss of nitrogen fertiliser from soils.
Example: methanogens in cattle guts release methane.
Key idea: the diversity of electron acceptors reflects microbial adaptation to different environments.
Frequently asked questions
What is Anaerobic Respiration in Prokaryotes?
Bacteria use alternative terminal acceptors such as nitrate or sulfate in the electron transport chain.
Which area of biology covers Anaerobic Respiration in Prokaryotes, and how advanced is it?
Anaerobic Respiration in Prokaryotes is one of the 53 topics in Metabolism & Bioenergetics. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Aerobic and Anaerobic Respiration, Chemosynthesis, Oxidative Phosphorylation.
Can you give an example of Anaerobic Respiration in Prokaryotes?
Shewanella can respire metals.
What should I learn before Anaerobic Respiration in Prokaryotes?
Work through the Beginner topics in Metabolism & Bioenergetics first, such as Metabolism, Anabolism and Catabolism, ATP, then return to Anaerobic Respiration in Prokaryotes. Advanced topics assume the Intermediate vocabulary.
What topics are related to Anaerobic Respiration in Prokaryotes?
The closest topics to Anaerobic Respiration in Prokaryotes are Aerobic and Anaerobic Respiration, Chemosynthesis, Oxidative Phosphorylation, Electron Transport Chain. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Anaerobic Respiration in Prokaryotes?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Anaerobic Respiration in Prokaryotes. To practise the whole of Metabolism & Bioenergetics, use the Metabolism & Bioenergetics quiz.
How is Anaerobic Respiration in Prokaryotes different from Aerobic and Anaerobic Respiration?
Anaerobic Respiration in Prokaryotes: Bacteria use alternative terminal acceptors such as nitrate or sulfate in the electron transport chain. Aerobic and Anaerobic Respiration: Aerobic uses oxygen for a large ATP yield; anaerobic occurs without oxygen with much less ATP. Read both side by side and note what each one explains.
How should I study Anaerobic Respiration in Prokaryotes step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Aerobic and Anaerobic Respiration and explain the difference aloud. Finally, take the Metabolism & Bioenergetics quiz and come back to this page for any question you miss.