Let me share with you a difference between light dependent reaction and light independent reactions.
| Aspect | Light-Dependent Reactions | Light-Independent Reactions or Calvin Cycle |
| Occurrence | Thylakoid membrane within the chloroplast | Stroma of the chloroplast |
| Initiation | Initiated by the absorption of light by chlorophyll | Relies on the products such as ATP and NADPH from the light-dependent reactions |
| Primary processes | · Photolysis of water to release oxygen and electrons
· Generation of ATP and NADPH |
· Carbon fixation (CO2 is converted into organic compounds) · Reduction of 3 phosphoglycerate to form glucose and other carbohydrates |
| Reactants | · Water
· light · ADP · inorganic phosphate |
· Carbon dioxide
· ATP · NADPH |
| Products | · Oxygen
· ATP · NADPH |
· ADP and inorganic phosphate (Pi)
· NADP+ and H+ · Carbohydrates (glucose) |
| Energy source | Light energy from the sun | ATP and NADPH produced during the light-dependent reactions |
| Dependency on light | Requires light for the activation of chlorophyll | Can occur in the absence of light |
| Role in carbon fixation | Does not directly fix carbon | Fixes carbon dioxide during the synthesis of carbohydrates |
| Time of occurrence | Occurs during the day in the presence of light | Can occur during both day and night |