RESPIRATION
Respiration is aerobic oxidation of molecules of nutritives. During the process of respiration organic molecules, for example, glucose, are oxidized by molecular oxygen, and C=O-bonds are formed. These bonds contain less free energy than the initial bonds: C-H, C-OH, C-C. Thus during respiration energy is generated. While in the process of photosynthesis, on the contrary, the energy of photons is used for reduction of CO2 accompanied by forming of compounds with more amount of free energy.