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 ...view middle of the document...
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 diffuse through the membranes and I arrived in the mitochondrial matrix. Thinking that I was now out of harm’s way, I let out another sigh of relief. Then I was pulled into a process call oxidative phosphorilation. And just by the name of the process, one could tell it was not going to be a happy ending. I was transported through one phospholipid bilayer and then right back through it again. When I thought not having control of where I was going was bad, something even worse happened- Chemiosmosis. I was used and abused and violated in so many ways. I was converted into carbon dioxide, a waste product of oxidative phosphorilation, to make Adenine Triphosphate, the energy of the cell. When they were done with me, I was diffused out of the mitochondria and immediately diffused out of the cell where my ride was. Another red blood cell picked me up and I travelled down the superior vena cava where the other carbon dioxide molecules gathered in the right atrium. WHOOSH! Down into the right ventricle and out via a pulmonary artery to the web of capillaries again. I diffused through the capillaries, across the epithelium, and back into the air sac. Finally this horrid ride was almost over with. Just like that, a great wind pushed me up and out of the beast and the sun was still shining as bright as before my day was ruined. What started out as such a promising day, turned out to be, by far, the worst day of my short life. However, there is always tomorrow to look forward to. I mean, what could be worse than what I had already gone through, right?