136 PRACTICAL ORGANIC CHEMISTRY the CH 2 OH groups around carbon atom 2, this difference again disappearing in the straight chain form (V). It will be noted that carbon atom i in glucose is concerned with the formation of the ring, and that when the latter opens out, the free aldehyde group appears at this point. The grouping on carbon atom i may conveniently be called the "potential aldehyde group," and that on carbon atom 2 in the fructose molecule similarly the "potential ketone group." For an elementary study of the supars, it is not suggested that the student should remember the structure of the disaccharidcs: their chief and character-istic reactions will, however, be readily understood if the following facts arc borne in mind. Sucrose on hydrolysis with dilute acids, or with the enzyme invertase (or " su-crase," p. 514,) gives rise to one molecule of glucose and one molecule of fructose: C 12 H 22 O 11 + H 2 O = C 8 H 12 O 6 + C 6 H 12 O 6 sucrose glucose fructose In the sucrose molecule, union takes place through carbon atom i of the glucose
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 09/19/2011 for the course CHM 2211 taught by Professor Castalleano during the Fall '06 term at University of Florida.