Neuroscientist in residence Luke 'Groundskeeper Willie' Tulloch is in studio to demystify the krebs cycle / citric acid cycle. This complex chain of 1000s of chemical reactions can be confusing so Luke starts off with big picture energy transfer from the sun, dials in to the systems of human energy production and then digs down the the detail of ATP production - he's waaaaaay too smart for Rawdon & Tommy!