Glucose is formed through a complex series of reactions known as photosynthesis, which takes place in the chloroplasts of plant cells. Photosynthesis occurs in two stages: the light-dependent reactions and the light-independent reactions (also known as the Calvin cycle).
1. Light-Dependent Reactions: These reactions occur in the thylakoid membrane of the chloroplasts. During this stage, light energy is captured by pigments such as chlorophyll and used to generate high-energy molecules like ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate).
2. Light-Independent Reactions (Calvin Cycle): The Calvin cycle takes place in the stroma of the chloroplasts. It uses the ATP and NADPH produced in the light-dependent reactions to convert carbon dioxide (CO2) into glucose. This process is also called carbon fixation.
In summary, glucose is formed in the stroma of the chloroplasts during the light-independent reactions (Calvin cycle) of photosynthesis.