Photosynthesis Part II: Glucose Needs a New Agent

This is part III of a series on oil I am writing.  It’s going to take a little while to get to the price of a gallon of gas, but I hope you can enjoy the journey with me.  If you want to go back to the beginning start with Nothing Matters More than Oil, Nothing and Photosynthesis Part I: Oxygen Gets All the Press.

I friend of mine told me that a blog called Common Science shouldn’t have chemical equations.  Not being one for taking advice, here is a reminder on the equation for photosynthesis where plants take carbon dioxide from the air and water from the ground to make oxygen and glucose, which make everything else.

6 CO₂ + 6 H₂O  à C₆H₁₂O₆  + 6 O₂

So back to memories of high school chemistry.  After spending a class or two talking about how ancient plants and bacteria created the oxygen that we breathe, your teacher, at long last, probably started to focus on the other less-glamorous molecule on the right hand side of the equation, C₆H₁₂O_6, glucose. 

Glucose needs to hire a new agent to try to get the on the same billing as oxygen because the production of glucose in photosynthesis is the beginning of essentially everything.  Look down at yourself.  Most of the mass of your body other than water is carbon-containing molecules.  Carbon atoms make up most of the mass of your DNA, your muscles, your nerves, you brain, your heart, your lungs, your, well …., everything.  Essentially every single one of those carbon atoms began is journey on the way to becoming part of you as part of a carbon dioxide molecule, which bumped into a plant, got high by a ray of sunlight and was converted into a molecule of glucose. The cells in the plant use the back bone of the glucose molecule to start the construction of the rest of the plant.  Your body makes the molecules that it needs either from eating plants or eating animals that ate the plants for you (a convenience for children who don’t like spinach or broccoli).

The other really, really important part of the glucose story is that the plant is capturing energy from the sun and storing it in the chemical bonds of the glucose molecules.  This energy captured in photosynthesis provides all of the caloric energy for all food for all animals on earth (including us) and the vast majority of the energy which fuels modern society. 

Over the next couple of blog entries I am going to expand on the theme photosynthesis of being the center of everything for us, the most fortunate residents of Chapelboro.  As you read this last paragraph look down at your computer.  Most of you computer is built of plastic.  Plastic is built from hydrocarbon polymers, nearly all of which originate with the glucose made from plants. Further, approximately 70% electricity running your computer right now comes from releasing the energy captured by photosynthesis and released somewhere in a power plant by burning the remains of a plant and returning the carbon back to the air as carbon dioxide where it started.  Cue the “Circle of Life” music.

Now that we have covered photosynthesis we can move on to Petroleum next week and one step closer to explaining why the rise in prices at the pump are caused by something other than those “evil speculators”.

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