The most correct thing to say is that mitochondria produce ATP in order to release energy (as hydrolysing ATP releases energy) but if I remember correctly at AS you can say 'energy in the form of ATP', you can't at A2 (there is an entire energy module at A2 so you should know the difference by then)
(Original post by Abbers)
Can someone check whether this is right? Mitochondria produce energy in the form of ATP.
mitochondria are the "powerhouse" of organism in which ATP is producing all the time. They are support e.g. metabolizations in a certain degree. In so far you are right. Anything else what do you want?