What is the general photosynthesis equation?

• A. 6 CO2 + 6 H2O + light energy -> C6H12O6 + 6 O2
• B. 6 CO2 + 6 H2O + heat energy -> C6H12O6 + 6 O2
• C. 6 CO2 + 6 H2O + light energy -> C6H12O6 + 6 O2 + energy
• D. CO2 + H2O + light energy -> glucose + O2

Answer: (A)

Photosynthesis uses light energy to build a carbohydrate from carbon dioxide and water, storing energy in chemical bonds. The general form shows six CO2 molecules and six H2O molecules reacting with light to produce one molecule of glucose (C6H12O6) and six molecules of O2. This equation balances atoms: six carbons from CO2, along with the hydrogens and oxygens from water, end up in glucose, while the extra oxygens are released as O2. The energy input must be light energy, not heat, and energy is not a product of the reaction; having energy on the product side would misrepresent how the process works. An incomplete or unbalanced form that omits the correct coefficients or uses an incorrect energy term likewise doesn’t reflect how photosynthesis operates.