What is the difference between anaerobic respiration and Fermentation?
First things first, anaerobic respiration and fermentation are completely separate pathways. Aerobic and anaerobic respiration involve an electron transport chain in the membrane. In aerobic resp the terminal electron acceptor is oxygen and in anaerobic resp it is something else (e.g. nitrate, sulfate, fumerate, malate, etc). Fermentation, which occurs anaerobically, is a pathway where NADH (or some other reduced electron acceptor-generated by the pathway) gets reoxidized by the metabolites of the pathway. Basically instead of the electron carriers reoxidizing NADH, in fermentation they dispose of electron in an “electron sink,” which is then excreted into the medium (e.g. alcohols, solvents, organic acids). Also, this occurs in the cytosol, not the membrane.