The Extended Beauty Of Photosynthesis

Now that we're well past the start of Spring, you're probably inured already to all the green.

I mean, after those long months of winter, everyone's pumped about the first buds and shoots — so bright green and promising. But then, it's all ho-hum, leaves everywhere — whatever.

Well, not me, pal.

See, this Spring I've been digging in on photosynthesis for some research I'm doing and, I gotta tell you, it's blowing my mind.

Now, for those of you who've been out of a bio class for a while, let's remember that photosynthesis is the molecular-scale shennagans plants use create food from sunlight.

But why, exactly, is photosynthesis worth freaking over, a bit? Well, let's jump into my way-back machine!

When life first formed on Earth about four billion, or so, years ago, the only way single-cell critters could get energy was from chemistry. They had to find high-energy chemicals like methane and covert them into low-energy chemicals like carbon dioxide. What was left over they used for, well, you know, being alive.

But it was hard times. The chemical foodstuff like methane was limited. That kept life from doing what it likes best — reproducing like crazy to take over the entire planet.

So, from life's point of view, the situation back then was a little like trying to run a marathon on diet of saltines.

But, then, evolution got creative. Really creative. The sun sends the Earth the energy equivalent of 8,000 atomic bombs every second. Eventually life, through evolution, figured out how to directly tap the energy in all of that sunlight. By combining light particles with molecules of carbon dioxide and water, photosynthesis opened the energy floodgates — freeing life from its starvation diet.

Did I mention life taking over the world? Because that's what happened. Literally. Using photosynthesis, life changed the entire planet. If you think I'm exaggerating, take a deep breath.

The atmospheric oxygen you're sucking in is only there because of photosynthesis. If it stopped, the oxygen in the air would react away pretty quickly. And why is oxygen so important for the Earth's history? For starters think of big brains, like the kind we have knocking around our skulls. They would never have evolved without the high-powered biochemistry oxygen allows.

So that means you can thank photosynthesis for even thinking about thanking photosynthesis.

Oh yeah, you can thank photosynthesis for our planet's characteristic blue-green color, too, since chlorophyll molecules, which are essential to photosynthesis, just love reflecting green light.

So there you go. From ocean plankton to Venus Flytraps, inside every plant there is an insanely complex little molecular engine that turns sunlight into food. Across billions of years, life figured out how to pull off this trick and, in the process, photosynthesis shaped the history of the entire planet. Not bad for a bunch of biomolecules.

So, thank a leaf next time you see one — and celebrate the glory of the green. The glory that is photosynthesis.

Adam Frank is a co-founder of the 13.7 blog, an astrophysics professor at the University of Rochester, a book author and a self-described "evangelist of science." You can keep up with more of what Adam is thinking on Facebook and Twitter: @adamfrank4

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