Glucose

Glucose is a simple sugar with the molecular formula C₆H₁₂O₆. It is a six-carbon monosaccharide and an important source of energy for living cells.

Structure

Glucose is an aldose: its open-chain structure contains an aldehyde group. In water it occurs chiefly in ring forms, including alpha and beta forms that differ at the anomeric carbon. Fructose has the same molecular formula but a different arrangement of atoms. Glucose units also form components of larger carbohydrates, including starch, glycogen and cellulose. Their different linkages give these polymers different properties.

Role in metabolism

Glucose connects energy storage with energy use. Photosynthetic organisms use energy from light to build carbohydrates from carbon dioxide and water. Cells can subsequently break down glucose through a sequence of metabolic reactions, transferring part of the available energy into adenosine triphosphate (ATP). ATP then supports many energy-requiring cellular processes.

The overall aerobic conversion is often summarised as glucose plus oxygen yielding carbon dioxide, water and released energy. This equation describes a net result: it is not a single cellular reaction. The pathways involve intermediate compounds and regulated steps. Building carbohydrates and breaking them down are examples of the anabolic and catabolic sides of metabolism, respectively.

Energy stored in carbohydrates also passes between organisms through feeding. The biochemical role of glucose therefore links cellular activity with the movement of energy through ecosystems.

Attribution

Prepared with reference to the structure and linked topics of the English Wikipedia article, revision 1377860044. Rewritten and checked against the sources cited above; changes have been made. Wikipedia contributors’ material is available under CC BY-SA 4.0.