FIGURE 2.

Distribution of energy in photosynthesis. (A) Total energy of the sun is partly not in the photosynthetic 400–700 nm region and is partly reflected, absorbed, or transmitted by leaves. The remaining energy is used in photosynthesis and is called intercepted photosynthetic energy (q, shown in orange). (B) Intercepted photosynthetic energy is not the actual energy used by the plant. A part is lost due to quantum efficiency requirements, in conversion to glucose, and in dark and photorespiration. The remaining energy is usable photosynthetic energy (Δ_psG, shown in orange). (C) Usable photosynthetic energy is used partly to provide energy for biosynthesis (Δ_bsG) and partly dissipated to make growth occur at a desired rate (Δ_DFG).