With two acetyl coenzyme As inside the mitochondrial matrix , we are finally able to start the steps of the citric acid cycle , or second stage of cellular respiration. The citric acid cycle is also known as the Krebs cycle . No matter what you call it, you'll notice the name fits the bill. This stage of cellular respiration is a cyclical process of 8 different chemical reactions. While all the reactions that occur are important, in this lesson, we're just going to focus on the reactions that are essential to create products that are important to the next phase of cellular respiration.