I got two hours of sleep a day, which is not enough, although four hours would be sufficient. In order to get more sleep this time I'm going to try to reduce the amount of air-traffic control communication that I have to do, so that I'm not constantly on the radio. NOVA: Your last flight lasted a little over six days.
Alpha and beta glucose differ in stereochemistry at one single carbon. In the alpha-form, a bulky group is in a so-called axial position, and in the beta-form, the group is in a more favourable equatorial position. These different positions lead to different bonds in polysaccharides, giving rise to a need for different enzymes to digest them.
In solutions, the open-chain form of glucose (either 'D-' or 'L-') exists in equilibrium with several cyclic isomers, each containing a ring of carbons closed by one oxygen atom. The D-glucose can exist in two forms alpha-D-glucose and beta-D-glucose. They differ only in the direction that-H and-OH groups point on carbon 1 (See the jmol images below). When alpha-glucose molecules are joined chemically to form a polymer starch is formed.