Well, the answer to that question basically depends on the type of shuttle that the cell actually uses. Some cells, such as skeleton muscle cells, use a shuttle known as the glycerol threephosphate shuttle. And in this particular case, the high energy electrons are transported onto complex three of the electron transport chain. And so what that means is we bypass complex one. And in this particular case, 1.5 ATP molecules will be formed when a single NADH produced in glycolysis moves onto the electron transport chain. So that means because we form two NADH molecules, two multiplied by 1.5 is three.