And once inside the blood plasma, a carrier protein molecule known as serum albumin picks up these fatty acids and then brings them to target cells. So let's suppose we have some type of target cell, let's say a muscle cell, and this is a cell membrane of that target cell. So in stage two, once the fatty acids are brought into the cytoplasm of that target cell, that cell needs to activate the fatty acids and then transport the fatty acids into the matrix of the mitochondria. Why is it the matrix? Well, because in stage three, within the matrix, those fatty acids are actually broken down into acetyl coenzyme A molecules. And then these acetyl coenzyme A molecules are fed into the citric acid cycle and that helps the cell generate ATP molecules.