A crop canopy's conversion of sunlight to stored chemical energy can be described as…
PHYSICS · Multi-part · Fermi University Physics · Biophysics & Medical Physics · Molecular machines, transport and bioenergetics · Molecular machines, transport and bioenergetics
Forces, Machines and Signals, Ch Proton gradients, ATP synthesis and photosynthesis
Problem
A crop canopy's conversion of sunlight to stored chemical energy can be described as a sequence of losses: of the incident solar energy, 45% lies in the photosynthetically active waveband; of that active radiation, 90% is absorbed by the canopy's pigments; of the absorbed energy, the photochemical machinery stores 20% as ATP and NADPH free energy (a photochemical efficiency lower than the 34% ceiling for red photons alone, because of reflection and non-photochemical losses); and of that stored chemical energy, 45% is subsequently spent on respiration and photorespiration before it appears as new biomass.
((a)) Translate this description into a loss waterfall, listing the energy remaining after each stage, from 100 units of incident sunlight down to units stored as biomass.
((b)) State the final percentage of incident sunlight energy stored as biomass and compare it with the Zhu, Long and Ort theoretical ceiling of 4.6% for C3 plants.