The potential energy changes into kinetic energy. :)
Because they are made to perform two different functions. Cells are part of tissues that are part of organs that perform a certain function. For example, your bone cells are made to make blood cells, so they wouldn’t be in your lungs as well.
<span>Amylase needs an optimum pH for its activity. It is in the range of 6-7. Below or above pH will denature this enzyme. The pH level is optimum for this enzyme in the mouth and hence it catalyses the break down of sugar. The pH level of stomach is lower than its optimum level duet to the activity of gastric acid. Hence the enzyme becomes inactive in the stomach.</span>