Which of the following statements regarding the ends of polysaccharides are true? 1) All polysaccharides have one, and only one, reducing end. 2) Some polysaccharides may have no reducing end. 3) Some polysaccharides may have no non-reducing ends. 4) All polysaccharides have a N-glycosidic bond at their reducing ends 5) Some polysaccharides may have a functional group other than a carbonyl group at their reduci ends.

Polysaccharides are polymers of monosaccharides. Multiple monosaccharides get bonded to each other via glycosidic bonds to form polysaccharides. If all the glycosidic bonds in a polysaccharide are between the same two carbon atoms of monosaccharides, then the polysaccharide will be linear. For example, in amylose (a polysaccharide), the monosaccharides are linked to each other via glycosidic bonds between the C1 of one monosaccharide and the C4 of the next monosaccharide ( glycosidic bond to be specific). Therefore amylose is linear.

In glycogen however, the main chain is composed of monosaccharides linked via  glycosidic bonds while branches arise as a result of  glycosidic bonds. Hence, glycogen is branched.

Polysaccharides have reducing and non-reducing ends. The reducing end is one with a monosaccharide with its anomeric carbon that is not involved in glycosidic bond formation. The nonreducing end has a monosaccharide whose anomeric carbon is involved in glycosidic bond formation. The anomeric carbon is the carbonyl carbon of the monosaccharide in its Fischer projection. The anomeric carbon of glucose is C1, while in fructose it is C2.