The Electron Transport Chain Is a Group of Membrane-Embedded Carriers

The electron transport chain is a group of membrane-embedded carriers that pass electrons from one to the next, while simultaneously pumping ________ across the membrane, generating a(n) ________.

A) glucose; proton motive force
B) hydrogen ions; electron gradient
C) electrons; ATP gradient
D) hydrogen ions; proton motive force
E) protons; electron motive force