Cellular Respiration Harvesting Chemical Energy ATP What?s the point? The point is to make ATP! ATP Harvesting stored energy Energy is stored in organic molecules carbohydrates, fats, proteins Heterotrophs eat these organic molecules ? food digest organic molecules to get? raw materials for synthesis fuels for energy controlled release of energy ?burning? fuels in a series of step-by-step enzyme-controlled reactions Harvesting stored energy Glucose is the model catabolism of glucose to produce ATP C6H12O6 6O2 ATP 6H2O 6CO2 ? + + + CO2 + H2O + heat fuel (carbohydrates) COMBUSTION = making a lot of heat energy by burning fuels in one step RESPIRATION = making ATP (& some heat) by burning fuels in many small steps CO2 + H2O + ATP (+ heat) ATP glucose