Which of the following processes generates a proton-motive force in mitochondria?
a. the reduction of nad+ by the first electron carrier in the electron transport chain
b. lowering of ph in the mitochondrial matrix the flow of protons through atp synthase
c. down their concentration gradient pumping of hydrogen ions
d. from the mitochondrial matrix across the inner membrane and into the intermembrane space

The correct answer is option d.

Explanation:

At the time of the electron transport chain, the transferring of electrons takes place from the level of higher energy to the level of lower energy at each of the steps that result in the discharging of energy. This energy discharged is utilized to pump the proton found in the matrix into the intermembrane space across the inner mitochondrial membrane.  

This process of proton pumping from the mitochondrial matrix to the intermembrane space results in a proton gradient, which is, utilized in the generation of ATP.  

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.