Carbon Cycle (2)

The first step in the utilization of CO2 by living organisms is photosynthesis by green plants. Carbon together with oxygen and hydrogen, in the presence of sunlight, is converted to simple carbohydrates. These in turn are synthesized by plants into complex fats and polysaccharides. The polysaccharides and fats stored in plant tissues are eaten by animals, which digest and resynthesize these carbon compounds into others.