Final answer:
The reducing end of glycogen is attached to the protein glycogenin via the anomeric carbon, which forms an alpha-1,4-glycosidic linkage with a tyrosine residue on glycogenin. This process is critical for initiating glycogen synthesis, with further elongation and branching of the glucose polymer being carried out by additional enzymes.
Step-by-step explanation:
The anomeric carbon is a central concept in understanding the structure of monosaccharides and their chemical behavior. In monosaccharides, the anomeric carbon is the result of the carbonyl carbon's reaction to form a cyclic structure, which results in a chiral center. Monosaccharides can form glycosidic bonds through their anomeric carbon, which is either an alpha (a) or beta (ß) anomer, depending on the orientation of the hydroxyl group attached to this carbon.
In the context of glycogenin, which acts as a primer for glycogen synthesis, the reducing end of glycogen is attached to a tyrosine residue on glycogenin through the anomeric carbon of a glucose residue. The linkage is a glycosidic bond, typically an alpha-1,4-glycosidic linkage. Glycogen synthase extends this primer by adding glucose units through the same type of linkage. During glycogenesis, the enzyme glycogen branching enzyme creates additional points of branching by creating alpha-1,6 linkages.
Knowing these details is essential for understanding the biochemical pathways involved in the storage and mobilization of glucose in the form of glycogen, and it demonstrates how the structure of sugars can affect their function within biological systems.