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.
Two of these cells produce the hormones insulin and glucagon. The beta cells create and secrete insulin. The alpha cells create and secrete glucagon. These two hormones are responsible for maintaining the glucose level in blood at a constant rate so that all the cells have the required energy to perform their functions.