The Linchpin of Life - Photosynthesis

The Linchpin of Life - Photosynthesis

I say, without hesitation, that this is the most important process of life as we know it.  No one should graduate from high school, be involved in public policy or industry, be a religious leader, be a parent or just be a person who cares about the future without a complete and thorough understanding this process, how it works and why it is critical.  It is the source of virtually all of our energy (with the exceptions of nuclear and geothermal energy) and key to understanding and solving most of our environmental problems  including global warming.

And yet, when most people are asked what "photosynthesis" is they give a "who cares" shrug of their shoulders.  Clearly the priorities of our education system are a tad confused.  

On the off chance that it may not be completely clear to you, you might want to stay tuned. . .


Photosynthesis sounds a bit like chemistry or, well boring.  It does, after all, have 5 syllables.  Let's break it down.

Photo means "light".  (Photography = picture (graph) from light)
Synthesis means "make or produce".

Photosynthesis simply means to make something from light.  Not so bad - right?

Make what?     Sugar.

Yes, sugar that stuff we love and love to hate.  Try for a bit to drop your prejudices one way or another; we will be talking a lot more about sugar and all its relatives shortly.  Just take my word for it right now that it is really really important and we should be very grateful for it.

Photosynthesis is dance of four substances (your science teacher called them chemical compounds,  but substances will do).

Water, carbon dioxide, sugar and oxygen.

What a plant can do, that you and I cannot, is take water, combine it with carbon dioxide and, given sunlight, produce sugar and oxygen.

carbon dioxide + water + sunlight   =     sugar + oxygen.

 (  For those who like the chemical explanation:

6CO2 + 6H20 + solar energy = C6H12O6 + 6O2  )

It is worth noting that at this point, oxygen is just a waste product because, chemically, there are too many oxygen atoms left over, so they are jettisoned.

The energy from the sun is held in the sugar molecule - sort of like a little battery.  

Whether you are in a well trimmed garden, an ancient forest, or a weed covered lot, you are seeing literally trillions and trillions of little factories trapping sunlight into sugar molecules made from water and carbon dioxide, and filling the atmosphere with needed oxygen - making life possible for the rest of us. 

Up next:  What does the plant do with all these trillions of sugar molecules?