The Krebs cycle<span> occurs right after glycolysis. The substance that begins the </span>Krebs cycle<span> is a 3-carbon molecule called pyruvic </span>acid<span>. The process breaks down the pyruvic </span>acid<span> into acetyl coenzyme A, releasing one of the carbon atoms into carbon dioxide.
Though some cells are bigger than others, they do not scale with size. For example if you look at skin cells on a dog they would be similar in size to a skin cell from a human. When an animal or species is bigger it is usually just made from more cells.
because it is hard to breakdown fat in a very short time while ATP can be broken down in a very short time.Fats have a very strong bond of molecular chains and this makes it hard to breakdown quickly