Science presenter Jon Chase describes how food provides us with the glucose that is needed for respiration. He demonstrates the reaction between the sugars in a jelly baby and molten potassium chlorate (V), which releases energy in a spectacular exothermic reaction.
Ask students if they know how many calories an adult man and woman need each day as part of a healthy and balanced diet. Can they suggest why there is a difference between the two sexes? Students could work in pairs to suggest how we can measure the energy released from a particular fuel. They could carry out a practical investigation to measure the energy released when different foods burn, held using tongs or on mounted needles below boiling tubes or copper beakers containing water. Practical tasks could be carried out to show differences between glucose and starch and how starch can be hydrolysed.