Glucose

Historical Background and Naming: Glucose was isolated from raisins in 1747 by Andreas Marggraf and discovered in grapes in 1792 by Johann Tobias Lowitz. The term ‘glucose’ was coined in 1838 by Jean Baptiste Dumas, while Friedrich August Kekulé proposed the term ‘dextrose’. Emil Fischer’s investigations led to an understanding of glucose’s structure. Chemical and Physical Properties: Glucose forms white or colorless solids and is highly soluble in water and acetic acid. It is poorly soluble in methanol and ethanol, melts at temperatures ranging from 146°C to 150°C, and has a pKa value of 12.16 at 25°C in water. Role in Energy Metabolism and Production: Glucose is the primary source of energy in organisms, stored as starch, amylopectin in plants, and glycogen in animals. It circulates in the blood as blood sugar and is released from glycogen breakdown in animals. Commercially, dextrose is manufactured from starches through pressurized steaming and enzymatic depolymerization. Significance in Medicine and Research: Glucose is an essential medicine listed by the World Health Organization and plays a crucial role in metabolism. Intravenous sugar solutions are used in medical treatments, and research on glucose metabolism has led to Nobel Prizes in Physiology or Medicine and Chemistry. Structural and Functional Properties: Glucose is a monosaccharide with six carbon atoms and an aldehyde group, existing in solid form as a monohydrate with a closed pyran ring. Glucose can exist in openchain and cyclic forms, with over 99% of molecules existing as pyranose forms in solution. It exhibits optical activity as d(+)glucose and undergoes mutarotation, switching between cyclic and openchain forms.