The high-energy electron travels down an electron transport chain, losing energy as it goes.
Some of the released energy drives pumping of \text H^+H+H, start superscript, plus, end superscript ions from the stroma into the thylakoid interior, building a gradient.
H^+H+H, start superscript, plus, end superscript ions from the splitting of water also add to the gradient.
H^+H+H, start superscript, plus, end superscript ions flow down their gradient and into the stroma, they pass through ATP synthase, driving ATP production in a process known as chemiosmosis.
