Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 12

Brown Fat and Thermogenin. Most newborn mammals, including human infants, have a special type of adipose tissue called brown fat, in which a naturally occurring uncoupling protein called thermogenin is present in the inner mitochondrial membrane. Thermogenin uncouples ATP synthesis from electron transport so that the energy released as electrons flow through the electron transport chain is lost as heat instead.
(a)What happens to the energy that is released as electron transport continues but ATP synthesis ceases Why might it be advantageous for a baby to have thermogenin present in the inner membrane of the mitochondria that are present in brown fat tissue
(b)Some adult mammals also have brown fat. Would you expect to find more brown fat tissue and more thermogenin in a hibernating bear or in a physically active bear Explain your reasoning.
(c)Given its location in the cell, suggest a mode of action for thermogenin. What land of an experiment can you suggest to test your hypothesis
(d)What would happen to a mammal if all of its mitochondria were equipped with uncoupling protein, rather than just those in brown fat tissue