How would you explain the following observation?
When 10,000 molecules of ATP are hydrolyzed to ADP and Pi in a test tube, about twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP.

Cells convert some of the energy of ATP hydrolysis into other forms of energy besides heat. This is something that happens to the body all the time. The body is like an enclosed space too. The energy of ATP does not always result in getting more heat.

A lot of times, the energy is used for different purposes. It can be used by people to move. It can be used by people to think. The energy received from the cells can be used for the various situations that people have to go through every day. Cells are very much efficient and even more so than non-living systems for sure.