A hydroxyl group is a functional group in organic chemistry consisting of an oxygen atom bonded to a hydrogen atom, represented as -OH. This group is commonly found in alcohols, where it contributes to the compound's properties, such as solubility in water. The presence of a hydroxyl group can significantly affect the behavior of molecules, making them more reactive and polar. Hydroxyl groups play a crucial role in various biological processes. For example, in carbohydrates like -glucose, the hydroxyl groups help in forming hydrogen bonds, which are essential for the structure and function of many biomolecules. Understanding hydroxyl groups is vital for studying organic compounds and their interactions.