ESPTs in biology photosynthesis and vision mechanisms

So far, we have seen proton transfers are fundamental molecular mechanisms in ordinary chemistry, particularly that part of chemistry that deals with acid/base reactions. In a 

The relative complexity of the proton transfer mechanism in bR or other photosensitive proteins explain why the mechanism of photosynthesis in plants is much less understood than that performed by H. salinarum, a bacterium that is much less familiar than green leaves. 

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