Final answer:
Dinitrophenol (DNP) makes the mitochondrial membrane leaky to protons, disrupting the normal proton gradient used for ATP synthesis, leading to energy dissipation as heat and potential weight loss.
Step-by-step explanation:
Dinitrophenol (DNP) uncouples mitochondrial electron transport from oxidative phosphorylation by making the inner mitochondrial membrane leaky to protons. This action results in the dissipation of the proton gradient that would normally be used to drive ATP synthesis via ATP synthase.
Consequently, rather than being used for ATP production, the stored energy is dissipated as heat. This heat dissipation can lead to weight loss, which is why DNP was used as a weight-loss drug until 1938. However, due to the dangerous side effects and the potential for overdose leading to hyperthermia and death, the use of DNP for weight loss is no longer considered safe or legal.