A green pigment found in plants, algae and cyanobacteria that allows them to process energy from sunlight. It uses the blue and red components of light and reflects the green radiation, making the leaves of plants appear green. There are several types of chlorophyll pigments. All have a magnesium atom in the centre surrounded by a ring containing nitrogen atoms, to this ring is attached a long hydrocarbon chain. Thanks to chlorophyll, photosynthesis takes place in the green parts of plants, converting water and carbon dioxide into simple sugars and starches with the energy of sunlight. The waste product of photosynthesis is oxygen.