Power in Cells
John E. Walker received his Chemistry degree and his D. Phil at Oxford. In 1974 he moved to Cambridge to join the Lab of Molecular Biology. He was awarded the Nobel Prize in Chemistry, with Paul Boyer and Jens Skou, for his work on how the enzyme ATP synthase catalyses the formation of ATP - the universal energy carrier in the living cell.
He has worked on the topic of how energy in food is channelled into the ATP molecule for more than 20 years. The key biochemical steps occur in the mitochondria, tiny energy producing factories found in most of the cells of higher organisms. Here energy derived from the oxidation ("burning") of sugars and fats is used to eject hydrogen ions (protons) from the mitochondria, thereby building up an excess of protons outside the mitochondria. This excess serves as an energy store (analogous to water in dam above a hydroelectric power station) that is channelled through the ATP synthesising machine (ATP synthase) to provide the energy that is stored in ATP. His studies have been aimed at understanding how the ATP synthase works. Surprisingly it is a rotary machine turning at about 100 times per second.
In 1998, he became the Director of the Medical Research Council's Dunn Human Nutrition Unit in Cambridge. Various aspects of the mitochondrion provide a major focus in the Unit's research programme.