Photosynthesis is the method by which plants, algae and some bacteria -- all autotrophs -- collect the sun's energy and synthesize sugars from carbon dioxide and water using light-absorbing pigments. These pigments include chlorophylls, carotenoids and phycobilins, often contained in special cell structures called chloroplasts. Oxygen is a reaction byproduct. Consumers or heterotrophs in a food chain need the sugars produced by autotrophs to survive.
Varieties of Sugar
Plants produce dozens of sugars including glucose, fructose and sucrose. Structurally different, glucose and fructose nonetheless have the same chemical formula: C₆H₁₂O₆. Plants will combine these two sugars to make sucrose, or table sugar, with the chemical formula C₁₂H₂₂O₁₁.
Photosynthesis can be written as a chemical formula:
6 CO₂ + 6 H₂O + λ → C₆H₁₂O₆ + 6 O₂↑
C is the symbol for carbon, H is hydrogen, O is oxygen and λ is light energy. The upward arrow indicates that oxygen gas is released.
The reaction of fructose and glucose to produce sucrose is
2 C₆H₁₂O₆ → C₁₂H₂₂O₁₁ + H₂O.
Plants converts glucose and fructose into sucrose, a more stable molecule to transport via the plant's phloem and for storage.