Glucose
Glucose is a type of sugar with the chemical formula C6H12O6. In humans, glucose is an important source of energy. During cellular respiration, energy is released from glucose, and that energy is used to help make ATP. Plants synthesize glucose using carbon dioxide and water, and glucose, in turn, is used for the energy requirements of the plant. Excess glucose is often stored as starch which is catabolized by humans and other animals that feed on plants.
Figure 1: Depending on the solution, glucose molecules form different isomers.