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.
Starches like amylose and amylopectin link only alpha-type glucose molecules together. With cellulose, it is the beta molecules that link together. The glycosidic bonds in cellulose have a different orientation from those in starch. As a result of this, human digestive enzymes can break down starch but not cellulose.