The Na-K ATPase [Enzyme Commission 220.127.116.11] was the topic of earlier blog post. Here I present the H(+)-Transporting ATP Synthase, Enzyme Commission 18.104.22.168. As shown in the diagram above, it is part of “respiratory chain” and “oxidative phosphorylation”. In the Roche Biochemical webpage it is located at “P” (shown in the diagram above) , and coordinate “10” (the bottom). The enzyme is a key membrane protein in aerobic cellular respiration. Note, in the diagram above: the formation of water from oxygen and hydrogen at the bottom, near the letter “P”.