ATP synthesis and the Mitochondria

Hey guys!

so we just had a little entertaining, CREATIVE, comic about cyanide. A few of you are probably wondering, how is atp made anyways? Yes there were a couple diagrams in the previously ingeniously creative comic strip, however I thought i’d go through a little more in depth with you just about just what REALLY goes on inside our little powerhouses (mitochondria) in our cells.


The chemiosmotic hypothesis explains how ATP is generated in the mitochondria :

Within the mitochondria, an ETC, or electron transport chain is found, where NADH and FADH containing electrons, have a high energy potential. This is located within the inner membrane of the mitochondria.

For simplification purposes, one can say that the ETC consists of four complexes which, within the ETC looses an electron, an oxidative process, giving off energy. Complexes 1, 3 and 4 uses this energy to pump protons into the membrane. Complex 2 does not use energy to pump protons even though energy is given off. It instead has succinate dehydrogenase from the TCA cycle, where FADH reacts

The high electrochemical gradient generated by these oxidative processes generates a high proton motive force.

How does it generate this force?

Well, protons cannot cross the inner membrane of the mitochondria matrix. It must therefore pass through an ATP synthase protein molecule, which must undergo a conformational change in order to produce ATP.

ADP + Pi —> ATP

This is generated from the electron motive force.

Cyanide, as seen in the previous comic, bind to comples 4, inhibiting the ETC from functioning.