So we see that cardiac muscle cells can use lactate molecules to form the ATP energy molecules and so by doing that, they essentially create this additional source of energy and they also conserve the glucose molecules inside the bloodstream by conserving the glucose molecules by using less glucose molecules or more lactate molecules. That basically means other cells can basically use the glucose to carry out different types of different types of processes. Now that's basically the first place where the lactate ends up. So cells such as cardiac muscle cells have special membrane proteins that can make the cell highly permeable to lactate. And once inside the cardiac myosides, the lactate can be transformed back into Pyruvate by lactate dehydrogenase and then fed into the citric acid cycle to generate ATP. Why?