What is the basic physics mechanism behind photosynthesis? Could a similar process be achieved artificially in a laboratory, with the same near perfect efficiency biological systems display.
Is there a sound simple theoretical model on how this works?
 A: The mechanism of photosynthesis has been extremely well-studied and is well-understood, but a full explanation would fill a good-sized textbook, of which dozens have been written over the years. Here is the most basic explanation I can come up with:
The beating heart of photosynthesis is an extremely complicated molecule called chlorophyll, in which a mgnesium atom is surrounded by organic molecules that are folded up around the iron in extremely complicated ways.
The shape and proximity of the electron clouds surrounding the those molecules affects the charge distribution of the electrons surrounding the magnesium atom in just such a way as to make it possible for photons of light to excite an electron in the magnesium-organic molecule system, which enables a chemical reaction to take place that stores the energy of the photon in another large and complicated organic molecule.
That stored chemical energy then is the driving force behind a long and extremely complicated cascade of other chemical reactions that constitute the metabolism of the plant containing the chlorophyll. In its simplest form, the overall chemical reaction takes light, carbon dioxide and water and converts it into oxygen and carbohydrate molecules (i.e., plant tissue).
The overall process is highly inefficient from an energy transformation standpoint but extremely effective nonetheless.
