tilakoidilumen
The thylakoid lumen is the internal compartment enclosed by the thylakoid membrane within chloroplasts and cyanobacteria. It is a crucial space for the light-dependent reactions of photosynthesis. Protons are pumped from the stroma into the thylakoid lumen by the electron transport chain, which is embedded in the thylakoid membrane. This proton pumping creates a proton gradient across the membrane, with a higher concentration of protons in the lumen compared to the stroma.
This electrochemical gradient is then used by ATP synthase to produce ATP, the energy currency of the