Expert: Walter Hintz - 11/1/2007

Question
how would animal life be affected by lack of oxgen in our atmosphere, in regard to celluar respiration.. i mean this question one would think is simple.. i know and any other schumk would know that without plants or autotrophs our oxgen levels would decrease and therefore we would have no oxgen to breath.. but this cellular stuff really confuses me.. with ATP, AND NADP, AND NAD, along with glycolysis i understand that it is a chemical reaction in the cytoplasm of  a cell. after that im lost. please help ..
?Eleanor

Answer
You have to look at the big picture Eleanora.  All energy comes from the sun and the nucleotides that you mention (ATP,NAD) store this energy in chemical bonds.  Living cells must have energy in order to carry out the life processes. The stored energy is released through an oxidative process. Some energy is released in the absense of O2( fermentation) but eventually oxygen must be utlilzed.
Glycolysis is the breakdown of glucose and the subsequence of converting ADP to ATP.
 The early Earth lacked atmospheric O2 and anaerobic organisms existed in the form of prokaryotes. If atmospheric disappears aerobes would disappear and anaerobes would again dominate.
 If you have any specific questions regarding cellular respiration please let me know.