PHYSICS 20E Lecture Notes - Lecture 12: Cellular Respiration, Pyrite, Photosynthesis
Document Summary
Creates glucose for plant biomass and food source for animals. 6co2 + 6h2o light energy c6h12o6 + 6o2. Oxygen waste product for plants, essential for animals and ozone layer. First life had no oxygen involved in energy product. First photosynthesis producing oxygen appeared 3 billion years ago. 1st cells with nuclei evolved (spike in o2) 1st land animals and plants (spike in o2) Why is oxygen important for complex life: aerobic respiration. Get energy via cellular respiration very efficient way to extract energy from organic compounds: ozone. As oxygen increased in atmosphere so did the level of ozone (o3) The ozone layer provides protection from ultraviolet sunrays. First o2 about 2. 3 byr ago from green algae. Only form in the absence of oxygen. Iron only dissolves in water that has low oxygen. Can only form in environments without significant oxygen. It"s easily dissolved out of rocks when oxygen is rich in the atmosphere.
