Carbohydrate Structure and Function : 4

Which of the two forms of starch is more soluble in the solution? Why?

Amylopectin is more soluble in solution than amylose because of its branched structure. The highly branched structure of amylopectin decreases intermolecular bonding between polysaccharide polymers and increases interaction with the surrounding solution.

Which of the diastereomers of glucose from the previous question are considered to be epimers of glucose? Enantiomers?

D-glucose's epimers are d-mannose (c-2), d-allose (c-3), and d-galactose (c-4). None of the d-stereoisomers is an enantiomer for glucose; l-glucose is the enantiomer of d-glucose.

Explain the difference between esterification and glycoside formation.

Esterification is the reaction by which a hydroxyl group reacts with either a carboxylic acid or a carboxylic acid derivative to form an ester. Glycoside formation refers to the reaction between an alcohol and a hemiacetal (or hemiketal) group on a sugar to yield on alkoxy group.

Regarding glycogen and amylopectin, which of these two polymers should experience a higher rate of enzyme activity from enzymes that cleave side branches? Why?

Glycogen has a higher rate of enzymatic branch cleavage because it contains significantly more branching than amylopectin.

From a metabolic standpoint, does it make sense for carbohydrates to get oxidized or reduced? Purpose?

It makes sense for carbohydrates to become oxidized while reducing other groups. This is the case because aerobic metabolism requires reduced form of electron carriers to facilitate processes such as oxidative phosphorylation. Because carbohydrates are a primary energy source, they are oxidized.