Identify the true statements regarding alpha-1,6 linkages in glycogen.
- The number of sites for enzyme action on a glycogen molecules is increased through alpha-1,6 linkages.
- New alpha-1,6 linkages can only form if the branch has a free reducing end.
- The reaction that forms alpha-1,6 linkages is catalyzed by a branching enzyme.
- These linkages can only be formed on a chain that is exactly 11 residues long.
- Branching increases glycogen solubility.