2,4-Dinitrophenol (DNP) affects electron transport and oxidative phosphorylation in mitochondria by binding to H+ ions in the intermembrane space, and then, because the 2,4-Dinitrophenol is nonpolar, and diffusing with the H+ ion across the mitochondrial membrane into the cytosol.

Problem 2

2,4-Dinitrophenol (DNP) affects electron transport and oxidative phosphorylation in mitochondria by binding to H⁺ ions in the intermembrane space, and then, because the 2,4-Dinitrophenol is nonpolar, and diffusing with the H+ ion across the mitochondrial membrane into the cytosol.

Explain why the pH in the intermembrane space increases after ingesting DNP. You may draw a diagram if it helps your explanation.

People who ingest this compound can suffer from fatigue. Explain all of the changes that would occur in the electron transport chain and oxidative phosphorylation after ingesting DNP and describe why these changes could lead to fatique.

After DNP was discovered in the 1930’s it was used as a dieting drug until it was taken off the market after too many people suffered severe side effects and some died. DNP, however, continues to be used by some body builders because it results in a rapid loss of fat. How does this drug, which affects cell respiration, result in a rapid loss of fat? Think about our discussion in class about how cell respiration is related to other catabolic and anabolic reaction pathways.