Ch 9

You have a racemic mixture of d-2-butanol and l-2-butanol. The d isomer rotates polarized light by +13.5∘. What is the rotation of the polarization of light of your mixture?

0

Arrange the order of events in the correct sequence for the conversion of β-D-galactose to lactose. 1) β-D-galactose-1-phosphate is converted to UDP-galactose. 2) ATP transfers a phosphate group to yield β-D-galactose-1-phosphate. 3) β-D-glucose reacts with UDP-galactose.

2-1-3

How many tripeptides can be formed from one molecule of each amino acid?

6 tripeptides

Select the statement that is incorrect. Complete the following sentences about carbohydrates.

All carbohydrates have the general formula Cn(H2O)n.

Which of the following are distinguishing features of different disaccharides? 1) the arrangement of different monomer units 2) the configuration of the anomeric hydroxyl group of each residue 3) the two specific sugar molecules and their stereoconfigurations 4) the carbons involved in the linkage

All of the listed items are features.

Which of the following monosaccharides are ketoses?

Answers 1, 3, and 4 are ketoses.

In a Haworth projection for glucose, what would be the position (above or below the ring) for the hydroxyl groups at C-2, C-3, and C-4?

C-2: below; C-3: above; C-4: below

What is a monosaccharide with 6 carbons and a ketone group called?

Ketohexose

Which of the following represent the function of glycoproteins, a group of biomolecules that contain both protein and carbohydrates? 1) They can serve as hormones. 2) They are involved in cell adhesion and cellular recognition. 3) They help in transporting suspended lipids through bloodstream. 4) They can serve as an aid to increase the viscosity of various bodily fluids.

Only statements 1, 2, and 4 are correct.

Which of the following compounds is not a monosaccharide?

Sucrose

What is the structural relationship between glucose and galactose?

They are epimers.

Synthesis of sugar polymers is enzyme catalyzed and requires activated monomers like ________ in lactose biosynthesis.

UDP-galactose

Which storage polysaccharide has the following characteristics?is a polymer of glucosehas α(1→ 4) linkagesis largely helical in its structure

amylose

Which of the following polysaccharides are NOT constituents of the fibrous parts of plants?

glucans

Maltose has a (1→4) α linkage between glucose and ________.

glucose

Two monosaccharides are joined by a __________ to make a __________.

glycosidic bond, disaccharide

Classify the carbohydrate tagatose by both the carbonyl group and the number of carbon atoms.

ketohexose

Which sugar molecule listed below has the following name?β-D-galactopyranosyl(1→ 4)β-D-glucopyranose

lactose

In the following Fischer projection, the hydroxyl group on the chiral carbon furthest from the carbonyl group points _____, meaning that this is the _____ isomer of mannose.

left / L

Is your list exhaustive?

no

In the following Fischer projection, the hydroxyl group on the chiral carbon furthest from the carbonyl group points _____, meaning that this is the _____ isomer of tagatose.

right / D

Which of the following sugars would NOT yield a positive Fehling's test (red color change)?

sucrose