<prompt> Thermogenin is present in ?CytoplasmMitochondriaRibosomeNucleus  <response>: Ans. is b i.e.,Mitochondria Thermogenin is found in mitochondria of brown adipose tissue.Thermogenin is an uncoupler protein present in brown adipose tissue brown fat.It uncouples oxidation and phosphorylation by acting as a channel for Fl ions so that hydrogen ion gradient cannot build up.Oxidation occuring in brown adipose tissue without generation of ATP results in production of heat. 