Both DNP (2,4-dinitrophenol) and thermogenin uncouple mitochondrial electron transport from ATP synthesis. Oxygen consumption and the oxidation of NADH both increase, but no ATP is synthesized. Thermogenin is expressed in the mitochondria of brown fat cells in newborn animals and adult mammals that hibernate. DNP was marketed in the 1930s as a diet pill, but in addition to causing weight loss it sometimes caused death.
a. Compare/contrast the mechanisms by which these uncouplers affect ATP synthesis. (4pts)
b. Why is the presence of thermogenin beneficial to babies and hibernating animals, whereas taking DNP as a diet pill has a high chance of killing you? (3pts)