Plants produce glucose through a process known as photosynthesis. Plants absorb the materials it needs and carry out chemical processes that transform these materials into glucose, which plants need for energy.
To produce glucose, a plant needs water, which it absorbs using roots and transports to the leaves. The plant opens its stomata, which are tiny holes on leaves, to obtain carbon dioxide. The plant also uses specialised molecules known as chlorophyll to obtain energy from light.
Using energy from light, the plant turns water and carbon dioxide into glucose and oxygen. The chemical reaction requires six molecules of water and six molecules of carbon dioxide to produce one molecule of sugar and six molecules of oxygen.
Photosynthesis occurs in two stages. Light-dependent reactions turn light into energy-carrier molecules. Light-independent reactions use the energy carrier molecules to form the glucose molecules and can occur with or without light.