Chapter 9, Problem 11PIAT

Does the Fountain of Youth spring from the mitochondrial proton gradient?

For thousands of years, explorers have sought mythical waters that promote a long life. In modern times, the quest for extending the human life span continues. Current research points to changes in the mitochondrial electron transport chain and the proton gradient as a cause of aging. How is the ETC involved in aging? Can it be manipulated to increase longevity?

Research has shown that cellular damage associated with aging occurs via the formation of oxygen radicals called reactive oxygen species (ROS). These radicals are produced when an excessive proton gradient across the inner mitochondrial membrane slows down the rate of electron transport in the ETC. Propose a hypothesis to explain how a proton gradient can reduce the rate of electron transport.