Now, if there is oxygen present in the cell, then the cell can undergo reaction known as aerobic cellular respiration, in which the two pyruvate molecules formed in the cytoplasm of the cell via the the process of glycolysis are then transported into the mitochondrial matrix of the mitochondria of that cell. And once within the mitochondrial matrix, the two pyruvate molecules are transformed into two acetylcoenzyme A molecules via a process known as pyruvate decarboxylation. Now, once we form the two acetylcoenzion A molecules in the mitochondrial matrix, they will then enter a cycle known as the citric acid cycle, also known as the crept cycle, also known as the tricarboxylic acid cycle, or simply TCA. Now, the citric acid cycle is basically a series of eight steps, a series of eight reactions, as shown in the following diagram. We have 123-4567 and eight. Now, the entire purpose of the citric acid cycle is to basically take the energy that is stored within our acetyl coenzyme A and transfer that energy in the form of high energy electrons to our electron carrying molecules, our NADH and Fadh, too.