Affinity

I wait for my friend at a café for coffee and think. Lost in thought, I take a deep breath and bite into my apple. And consider, how this air I breath and food I eat will unite. Two seemingly unlikely bedfellows from different worlds, paths poles apart, with an uncanny affinity for each other. These two; molecular oxygen and a 6-carbon glucose molecule will couple and fuel my thoughts.

In air, molecular oxygen enters at 21%, it’s all I need, no more, no less, (please) and beelines down a series of ever diminishing bronchial channels to my alveoli of crowded, dead-end cul-de-sacs bathed in a river of transport services. No time to linger, oxygen diffuses out into a rich flowing liquid medium, is snatched by a passing red corpuscle, and buckles in to one of hemoglobin’s four seats provided. Flowing in my bloodstream, while holding on through turbulent vessels, and drifting through laminar capillaries, it approaches its destination, unbuckles, diffuses into my thinking nervous cells, and waits.

Hustling, my 6-carbon glucose molecule enters a straight-line pathway and…chop chop…. is sliced into three 2-carbon energized fragments during Glycolysis. At a crossroads, without oxygen, my fragments will waste away in a lactic acid broth. But oxygen awaits and a gateway opens to a Ferris wheel of activity in the Krebs cycle, disarticulating the carbon skeleton into high energy electrical charges.

And here the magic happens. Cellular Respiration. The high energy electrical charges cascade down a series of redox waterfalls, pumping protons across the border, only later to have them zipping back through and spinning a rotary motor that generates the energy currency (ATP) for my pondering nerve cells. At last, the final chunk of the original 6 carbon glucose molecule, unrecognizable, bonds with affinity to a radicalized oxygen to form carbon dioxide, and I breath out.

My friend has arrived, and I think about the different worlds we come from and the disparate paths we have taken.

And I wonder how it is that we have connected and bonded so tightly.
Ahh, yes……affinity.