Uses of glucose

The glucose produced in photosynthesis is used in five main ways:

1. Respiration — releasing energy for the plant's cells.
2. Starch — converted into insoluble starch for storage.
3. Cellulose — used to make cellulose, which strengthens cell walls.
4. Fats and oils — converted into fats or oils for storage, e.g. in seeds.
5. Amino acids — used to make amino acids, which are built into proteins.

Glucose is soluble, so storing it would affect the movement of water into and out of cells by osmosis. Instead, plants convert it into starch, which is insoluble. Starch is stored in roots, stems and leaves, ready for use when photosynthesis isn't happening, such as at night or in winter.

Plants also convert glucose into fats and oils for storage — especially in seeds, where they provide energy for germination. Many vegetable oils, such as sunflower and rapeseed oil, come from seeds.

Cellulose is made from glucose and is used to build and strengthen plant cell walls.

To make amino acids, glucose is combined with nitrate ions absorbed from the soil through the roots. The amino acids are then joined together to make proteins, such as enzymes. Without enough nitrates, a plant can't make enough protein and its growth is stunted.