A linear oligosaccharide is composed exclusively of glucose units ( C₆H₁₂O₆ ). If one molecule of this oligosaccharide contains exactly 31 oxygen atoms, how many glucose units are present in it?

Step-by-step solution

Let the number of glucose units in the linear oligosaccharide be n . Each glucose monomer ( C₆H₁₂O₆ ) contributes 6 oxygen atoms, giving an initial total of 6n oxygen atoms. To link n monomers in a linear chain, (n-1) glycosidic bonds must be formed. Each glycosidic bond is formed via a dehydration reaction that releases one molecule of water ( H₂O ), thereby removing 1 oxygen atom. The total number of oxygen atoms lost as water is (n-1) . The final number of oxygen atoms in the oligosaccharide is 6n - (n-1) = 5n +