Aldoses are a type of simple sugar, or monosaccharide, characterized by the presence of an aldehyde group (-CHO) in their molecular structure. They are important in biochemistry and serve as fundamental building blocks for more complex carbohydrates, such as disaccharides and polysaccharides. Common examples of aldoses include glucose and galactose. In terms of their structure, aldoses can vary in the number of carbon atoms they contain, typically ranging from three to seven. The classification of aldoses is based on the number of carbons, leading to terms like trioses (three carbons) and pentoses (five carbons). These sugars play crucial roles in energy metabolism and cellular functions.