Fat is used as a form of energy when the body really needs it. where as an enzyme is used to speed up a reaction in the body or might be needed to start a reaction in a body.
Explanation: The pituitary gland is nicknamed the master endocrine gland because it releases hormones that controls other parts of the endocrine system. It also controls the activity of the thyroid by releasing the Thyrod Stimulating hormone, TSH.
