A Day in the Life of an Oxygen Molecule

Michael Goetz
Pd. 7 AP Biology
“A Day in the Life of an Oxygen Molecule”
So today started out like any other day, floating around and just going with the flow.   It was a beautiful Monday afternoon.   The sun was shining, the birds were singing, and I thought to myself, “Today is going to be a wonderful day!”   However, I was sadly mistaken.   I decided to float closer to earth to see what all the other walks of life were up to today.   I was down near the earth for only a minute when I felt a tug backwards.   I looked behind me and saw a horrific sight.   A human’s mouth was where I was being pulled into.   The bright sun’s light began to fade as I went into the mouth of the beast.   Then down the trachea and into the left lung I went.   Once in the lung, I was transported to an air sac where I saw many other air molecules gathered.   Upon contact with the moist film of the air sac, I was immediately diffused across the epithelium and into a web of capillaries.   Now inside of the capillary, I was whisked away on a red blood cell via a pulmonary vein.   My first destination was the left atrium, thinking it was all over I let out a sigh of relief.   Then I dropped into another chamber, which I later found out was the left ventricle, and was pumped out through the aorta.   Racing through the aorta, I was now completely vertical and still going just as fast as before.   I then leveled off and was diffused through a lipid bilayer.   I made an educated guess that I was now in a brain cell of the human.   I started to look around the cell seeing the endoplasmic reticulum, the Golgi apparatus, and the nucleus.   I then saw an organelle that looked like a football, so I decided to investigate.   That was one idea I wish I would have never thought of.   When I arrived at the football organelle, I had realized that it was enclosed by two membranes, which were both made of a phospholipid bilayer.   I then came to the conclusion that this organelle was in fact mitochondria.   I proceeded to...