What are the structural differences between \(\alpha\) - and \(\beta\) -glucose? These two cyclic forms of glucose are the building blocks to form two different polymers. Explain.

α-glucose and β-glucose are two different isomers of glucose, which means they have the same molecular formula but different structural arrangements. The difference lies in the orientation of the OH group on the first carbon atom (anomeric carbon). In α-glucose, the OH group is below the ring structure (i.e., on the same side as the CH2OH group), whereas in β-glucose, the OH group is above the ring structure (i.e., on the opposite side of the CH2OH group).

The two polymers that can be formed from α-glucose and β-glucose are called starch and cellulose, respectively. Starch is a polysaccharide made up of α-glucose molecules and is found in plants, serving as energy storage. Cellulose, on the other hand, is a polysaccharide made up of β-glucose molecules and is also found in plants as a structural component of their cell walls.

In starch, α-glucose molecules are linked together by α(1→4) glycosidic bonds, which form a helical structure. The orientation of the OH groups in α-glucose allows the formation of these bonds, and the resulting helical structure allows for easy packing and storage within plant cells. In cellulose, β-glucose molecules are linked together by β(1→4) glycosidic bonds, which form straight and linear chains. Unlike starch, the orientation of the OH groups in β-glucose allows the formation of hydrogen bonds between adjacent linear chains, thus creating a highly stable and rigid structure suitable for providing support and strength in the cell walls of plants. In summary, the structural differences between α-glucose and β-glucose lead to the formation of two different polymers, starch and cellulose, with distinct properties, serving different functions within plants. Starch, formed from α-glucose molecules, is an energy storage molecule with a helical structure, while cellulose, formed from β-glucose molecules, is a structural component of plant cell walls with a linear and rigid structure.