A drug that inhibits thermogenin function in an animal would reduce the animal's ability to generate heat. Thermogenin is likely found in the inner mitochondrial membrane and helps uncouple oxidative phosphorylation to produce heat. Brown adipose tissue is more abundant in small babies due to their higher heat loss and need for temperature regulation.
(a) A drug that inhibits thermogenin function in an animal would likely reduce the animal's ability to generate heat. Thermogenin is responsible for dissipating proton gradients in the mitochondria, which leads to the production of heat instead of ATP. Inhibiting thermogenin would therefore decrease heat production.
(b) Thermogenin is most likely to be found in the inner mitochondrial membrane, where it functions to uncouple oxidative phosphorylation and generate heat.
(c) The scientist's claim that thermogenin dissipates proton gradients in the mitochondria of brown adipose tissue is likely supported. As mentioned before, thermogenin uncouples oxidative phosphorylation and allows for the production of heat instead of ATP.
(d) Brown adipose tissue is more abundant in juvenile mammals, especially small babies, than in larger adults. This observation can be supported by the fact that newborns have a larger surface area to mass ratio, which leads to more heat loss. The presence of brown adipose tissue and its ability to generate heat helps regulate the body temperature of small babies.