My book shows this figure of Fischer formula of D-glucose:I don't understand this figure, and I wonder why the upper carbon atoms in both the right and left formulas have 5 bonds. And from where comes this hydrogen atom in the upper left side of the figure (attached to α-D-glucopyranose). When turning D-glucose to Fischer formula, it seems there's an additional hydrogen atom, isn't it? Why and how does this happen?!! Could someone explain how to get from the aldehyde form of glucose (the middle structure) to the β-D-Glucopyranose and the α-D-Glucopyranose?