<prompt> MELAS inhibit all ETC Complexes EXCEPT:IIIIIIIV  <response>: MELAS mitochondrial encephalopathy, lactic acidosis, and stroke MELAS inhibits complex I, III IV of ETC. It is an inherited condition due to NADH-Q oxidoreductase, Caused by a mutation in mitochondrial DNA Involved in Alzheimer disease and diabetes mellitus. ETC is affected, brain is affected and due to anaerobic metabolism, lactic acidosis occurs. 