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 open-chain 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 open-chain forms.https://en.wikipedia.org/wiki/Glucose