Photosynthesis is the process by which green plants make food. Photosynthesis takes carbon dioxide from the atmosphere and uses light energy to convert carbon dioxide and water to glucose and oxygen.
Photosynthesis takes place in the chloroplast of the plant cell. Chloroplasts are able to do this because they contain chlorophyll, a green pigment made using magnesium ions, which is able to absorb the energy in the light waves.
You need to know the formula for photosynthesis.
Carbon dioxide + water → glucose + oxygen
6CO2 + 6H2O → C6H12O6 + 6O2
This process is endothermic. This means that when photosynthesis is taking place, the plant absorbs heat energy from the surroundings and the temperature goes down.
Glucose formed from photosynthesis can be used in several ways by the plant.
- For respiration to release energy for growth
- It may be converted into insoluble starch for storage
- It can used to produce fat or oil for storage
- It is used to produce cellulose, which strengthens the cell wall
- It is used to produce amino acids for protein synthesis. To produce proteins, plants also use nitrate ions that are absorbed from the soil.