The Processes I Go Through

Hey there! I'm an oxygen molecule and today I am going to tell you about how I was created and how I go through cellular respiration. I was made by a tree in this process called photosynthesis. The short version is that this tree took in a bunch of carbon dioxide, water, and light energy from the sun. Using this energy and those molecules, it made glucose and I was created as a leftover waste product. After that, the tree threw me out and I floated through the air for a while. Eventually, some human breathed me in. Once he did that, I went through this other process called cellular respiration. I didn't have to do much in this process. I just waited around until eventually I got combined with some electrons and hydrogen ions. I then became a water molecule. As a water molecule, I went through photosynthesis again and the whole thing started again. The diagram below shows the cycle that I am constantly going through.