Electrochemical gradient in ATP synthesis?

Question

Am i right in saying it's electrical because H+ ions are moving into the intermembrane space and electrons are accumulating in the matrix (from electron transport chain)?

and

Am, I right in saying its a chemical gradient because there is a higher conc. of H+ ions on one side of the membrane than the other?

Answer 1

Yes, basically you're right.  Glucose is broken down in the cytoplasm but then the two three-carbon sugars are moved into the mitochondria, into the Krebs cycle.  In the Krebs cycle, there are a series of steps in which the sugars are broken down further, while Hydrogen ions are stripped off and reduce NAD or FAD.  The Hydrogens are essentially stored on one side of a membrane in the mitochondrion.  In allowing the hydrogens to move DOWN their concentration gradient (i.e., from an area of high concentration to an area of low concentration) through a membrane with an ATPsynthesizer in it, the energy they lose is translated into ATP.

It is electrical because the Hydrogen ions are charged, and chemical because is is dealing with a chemical.