In 1961, Mitchell proposed what would be called the chemiosmotic hypothesis. It is a theory which states that adenosine triphosphate, or ATP, synthesis in a respiring cell comes from the electromechanical gradient that is found across the inner membrane of mitochondria. It uses the energy of nicotinamide adenine dinucleotide (NADH) and the Flavin group, which is a group of organic compounds that is based on pteridine.
The energy is formed when glucose or other energy-rich molecules are broken down by the body.
When energy-rich molecules are metabolized, they produce an intermediate energy source that is equally rich. This is then coupled to the reduction of a carrier molecule within the mitochondrial matrix in order to pass electrons through the inner mitochondrial membrane and the to proteins within the electron transport chain.
This energy found within the electrons is then used to pump protons throughout the mitochondrial matric to store energy. The protons then move back across the membrane through the ATP synthase enzyme. This energy forms with inorganic phosphates to synthesize ATP. As a final step, the protons and electrons at the last stop of the electron transport chain are taken up by oxygen molecules and this forms water.
