1) Late-night TV ads are often quite educational. One advertisement touted the merits of eating grapefruit to lose weight. At that point, Dr. Blakeslee, in a lab coat standing in front of a blackboard covered with molecular formulas proceeds to explain how it is the citric acid in the grapefruit that burns up the fat and for only $XX you can get a month's supply of their pills. Use what you know about the citric acid cycle and fatty acid metabolism to deduce whether added citric acid causes weight loss.