Thermogenin is present in ?
Cytoplasm
Mitochondria
Ribosome
Nucleus
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.