The oxygen during photosynthesis comes from split water molecules. During photosynthesis, the plant absorbs water and carbon dioxide. After the absorption, the water molecules are disassembled and converted into sugar and oxygen. The water molecules are also split into oxygen and hydrogen and the latter (hydrogen) is joined to the carbon dioxide to create sugars. Excess oxygen gathered after all these are released into the atmosphere during respiration.
In another regard, plants take in carbon dioxide (CO2) and water (H2O) during photosynthesis. The Chlorophyll in the leaves absorb sunlight and the water and carbon dioxide are used for making sugar. This sugar is stored for energy. Excess sugar is left behind in the root to work as starch and the excess water and carbon dioxide will evaporate.
The oxygen released during photosynthesis comes from thesplitting of waterduringthe light-dependent reaction. 3. Remember, the electrons lost from the reaction center in photosystem II must be replaced.