In all academic sources, sucrose is identified as α−glucose (1-->2) β−fructose. However, I cannot find any explanation anywhere as to why the fructose monomer has to be in the β configuration. Maltose has both α and β anomers, same for lactose. Even trehalose, another non-reducing disaccharide with glycosidic linkage between two anomeric carbons, has α-α, α-β, and even β-β anomers. Why is sucrose special? And is there a disaccharide out there that has α−glucose (1-->2) α−fructose configuration?

  • $\begingroup$ Welcome to SE Biology. Please finish reading the Tour to learn how this site works. We allow just one question at a time, and if you wish to know whether a particular molecule exists it should be easy enough to determine its systematic name and do an internet search. As for the why question, why questions in biology can relate to either function or mechanics. In the case of disaccharides that function of which is nutrition, the answer is probably mechanical, and I imagine lies in enzyme structure and specificity. Check the structures of the synthases for these disaccharides. $\endgroup$
    – David
    Mar 22 at 22:53


You must log in to answer this question.

Browse other questions tagged .