ATP is a product of light-dependent reactions in photosynthesis. The ATP is produced in ATP-synthase an intramembrane enzyme that is a catalyst for
ADP+H2PO4(ionic phosphorus)⇒ATP+H2O.So it requires so far ADP and ionic phosphorus, but that's not enough. For the enzyme to work there needs to be a flow of protons through it. The protons result from the photolysis of H2O in photosystem I.H2O⇒<u><em>2[H]</em></u>+2e-+1/2O2. So far we need H+, <u><em>ADP, and ionic phosphorus.</em></u> But most importantly for those reactions to occur there needs to be light.
ATP requires light, carbon dioxide, and water to convert certain molecules of water into oxygen which is then converted into energy particles known as ATP.
The light-independent (or dark reaction) produces sugar-phosphate molecules, which are used as an important reactant in cellular respiration. Hope this helps!
