The by-product of photosynthesis is oxygen (O2). Photosynthesis is the process by which plants, algae, and some bacteria convert carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6) and oxygen (O2) using sunlight as a source of energy.
During photosynthesis, light energy is absorbed by pigments called chlorophyll, which are located in the chloroplasts of plant cells. This energy is then used to split water molecules into oxygen gas and hydrogen ions. The oxygen gas is released into the atmosphere as a by-product of photosynthesis, while the hydrogen ions are used to create energy-rich molecules like ATP and NADPH, which are used to power the synthesis of glucose.
In summary, the by-product of photosynthesis is oxygen (O2). During photosynthesis, plants and other photosynthetic organisms produce oxygen gas as a waste product, which is released into the atmosphere for other organisms to use in respiration.