In normal course, excess glucose gets stored in the liver as glycogen and if the levels are more it gets converted into fat and gets stored in liver as well as in adipose tissues. A primary role for the glucose molecule is to act as a source of energy; a fuel. Plants and animals use glucose as a soluble, easily distributed form of chemical energy which can be 'burnt' in the cytoplasm and mitochondria to release carbon dioxide, water and energy.
