"It's kind of like the cooking shows on television where the star comes out and cooks everything in 30 minutes. But before the star can do that, other people got everything ready -- bought the food, measured out spices into all those little cups, and sometimes cut up vegetables, .... The light-dependent reactions are like the process of getting everything set for the cooking show because these reactions get everything ready for the Calvin cycle. The 30 minute program with the star cooking the food is like the Calvin cycle because this set of reactions takes the prepared energy and hydrogens plus carbon dioxide from the air and actually builds the glucose. "