Exam 22: Carbohydrates

Many other sugars besides glucose exhibit mutarotation.For example,α-D-galactopyranose has [α]_D = +150.7^o,and β-D-galactopyranose has [α]_D = +52.8^o.Show how the equilibrium percentages of α and β anomers can be calculated from the equilibrium specific rotation of +80.2^o.

The D-glucose unit at the branching point of amylopectin has free hydroxyl groups at which positions?

Complete the reaction and give the structure and name of the product(s):

How many stereoisomers of the L series would exist for the following pentose? O=CHCHOHCHOHCHOHCH₂OH

Reaction of the following substance with bromine water would yield:

Which of the following substances will afford an optically inactive product upon reaction with nitric acid?

Cellulose lacks nutritive value for humans because:

Compound X is a reducing sugar which,on hydrolysis,affords two molar equivalents of D-glucose.This hydrolysis is catalyzed by an enzyme specific for glucosides of this type: What is the identity of X?

Refer to the structures below.Which sugar(s)would yield an optically active aldaric acid on oxidation with nitric acid?

An aldopentose,X,is subjected to a Kiliani-Fischer synthesis to produce two aldohexoses,Y and Z.Both Y and Z,when oxidized with nitric acid,yield optically active aldaric acids.Which structure represents X?

The simplest carbohydrates (those that cannot be hydrolyzed to simpler carbohydrates)are called ______________.

Which monosaccharide is recovered from the hydrolysis of glycogen?

What compounds (other than methanol)would be formed in the solution if glycoside presented below was treated with dilute aqueous hydrochloric acid and the solution allowed to stand?

An aldonic acid is represented by:

If the methyl glycoside of an aldohexose is treated with HIO4,one molar equivalent of HCHO is formed but no HCOOH.What size ring is present in the glycoside?

Draw the structure(s)of the $\gamma$ -lactone(s)that can be formed from D-Glucaric acid.

What can be said,correctly,about a monosaccharide,the name of which is preceded only by (+)?

Draw the structure of ethyl α-D-mannoside in Haworth projection.

Epimers are represented by:

The Kiliani-Fisher Synthesis is the reaction of an aldose with: