Which of the Following is NOT True of 2,4-Dinitrophenol (DNP)

Question

Which of the following is NOT true of 2,4-dinitrophenol (DNP)?
A) It is an uncoupler.
B) It can be used to measure $ \Delta $ pH.
C) Unprotonated DNP can cross the membrane.
D) Protonated DNP can cross the membrane.
E)It dissipates the proton motive force.

Accepted Answer

DNP is an uncoupler that causes the proton motive force to dissipate by allowing protons to leak across the inner mitochondrial membrane. Unprotonated DNP can cross the membrane, but once inside the matrix, it becomes protonated and unable to cross back out. This leads to an accumulation of protons in the intermembrane space and a decrease in the proton motive force. DNP is not used to measure ΔpH, but rather it disrupts it.