Question

What is photosynthesis? Name the organelle and the organs in which photosynthesis takes place. Where does the oxygen liberated come from during this process? What happens to the carbohydrates which are not immediately used by the plant?

Hint:

Chloroplasts are the sites of photosynthesis; oxygen is released from water splitting.

Answer 1

Green plants create their food (glucose) through photosynthesis, utilizing sunlight, carbon dioxide, and water. This is an anabolic and endothermic process.
- Location: Photosynthesis occurs within chloroplasts, which house the chlorophyll pigment.
- Structures: The primary sites for photosynthesis are the green leaves of the plant.
Oxygen is a byproduct of photosynthesis, originating from the photolysis of water molecules. Sunlight splits water into hydrogen and oxygen:
\[ 6CO_2 + 6H_2O \xrightarrow{\text{Sunlight, Chlorophyll}} C_6H_{12}O_6 + 6O_2 \] The oxygen released comes from water, not carbon dioxide.
Plants store excess carbohydrates as starch in leaves, stems, roots, or fruits for future use.