Assignment Carbohydrates Glycoconjugates PDF

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Name: __________________________ Date: _____________

1. From the abbreviated name of the compound Gal(  1 → 4)Glc, we know that: A) C-4 of glucose is joined to C-1 of galactose by a glycosidic bond. B) the compound is a D-enantiomer. C) the galactose residue is at the reducing end. D) the glucose is in its pyranose form. E) the glucose residue is the  anomer.

2. Starch and glycogen are both polymers of: A) fructose. B) glucose1-phosphate. C) sucrose. D)  -D-glucose. E)  -D-glucose.

3. Two aldopentoses, D-arabinose and D-ribose have the same absolute configuration but differ in one chiral carbon configuration. A) Five carbon monosaccharides B) Diastereoisomers. C) Epimers. D) A, B and C. E) B and C.

4. A glycoconjugate molecule may include a carbohydrate as well as: A) an amino acid. B) a lipid. C) a saccharide. D) both an amino acid and a lipid. E) an amino acid, a lipid, and a saccharide.

5. In a(n) _____ the carbonyl group is at the end of the carbon chain, but in a(n) _____ the carbonyl group can be at any other position. A) aldose; ketose B) ketose; aldose C) hexose; heptose D) aldose; hexose E) ketose; tetrose

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6. Which monosaccharide is NOT a six-carbon monosaccharide? A) fructose B) ribose C) mannose D) glucose E) galactose

7. Which arrow CORRECTLY identifies the atom that will become the anomeric carbon? Q34

A) B) C) D) E)

A B C D E

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8. Based on the form of the cyclic sugar shown below in a Haworth projection, which Fischer projection formula could have formed this structure?

9. Which modification CANNOT be made to a sugar molecule by an organism? A) oxidation of the carbonyl carbon B) replacing a hydroxyl group with an amino group C) oxidizing a carbon atom to a carboxyl group D) replacing a hydroxyl group with a hydrogen atom. E) All of the answer choices are possible sugar derivatives.

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10. What is the CORRECT name for the linkage between these monosaccharide derivatives?

A) B) C) D) E)

(1→4) ( 1→4) (1 4) (1→ 4) (1→4)

11. Which statement accurately describes the interactions between the molecules thrombin, antithrombin, and heparan sulfate? A) In the absence of heparan sulfate, antithrombin binds tightly to thrombin, inhibiting blood coagulation. B) In the absence of heparan sulfate, antithrombin cannot bind to thrombin, inhibiting blood coagulation. C) In the presence of heparan sulfate, antithrombin binds tightly to thrombin, inhibiting blood coagulation. D) In the presence of heparan sulfate, antithrombin cannot bind to thrombin, enabling blood coagulation. E) In the presence of heparan sulfate, antithrombin binds tightly to thrombin, enabling blood coagulation.

12. Which factor is NOT a part of determining the complete structure of an oligosaccharide or polysaccharide? A) determination of linear sequence B) determination of lectin partners C) determination of branching positions D) determination of glycosidic linkages E) determination of monosaccharide configuration

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13. The anomeric carbon of a monosaccharide: A) Assumes only one sterically stable configuration B) Is known as a reducing end in a hemiacetal or hemiketal C) Cannot mutarotate between two configurations D) A and B E) B and C

14. Which statement about proteoglycans is FALSE? A) They contain protein. B) They can affect ligand-receptor interactions. C) They are always extracellular. D) They contain glycosaminoglycans.

15. Both cellulose and amylose are homopolymers of D-glucose, whereby: A) Each monosaccharide is connected to the next via O-glycosidic bond B) Each monosaccharide is connected to the next via a condensation reaction C) Each monosaccharide is connected to the next, at C1-anomeric carbon of one to C4 of next. D) Cellulose and amylose contain one reducing end each. E) All of the above

16. Glycogen differ from amylopectin in one of several way: A) Monosaccharides in glycogen are connect at (alpha 1 to 4) B) Glycogen is made up of D-glucose C) Glycogen contains (alpha 1 to 6) branches D) Glycogen contains higher number of branches E) All of the above

17. Polysaccharides: A) do not fold into three-dimensional structures. B) are glycans. C) must be homopolysaccharides. D) are never branched. E) All of the above

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18. Categorize each of the following as an aldose, a ketose, or neither.

19. Define each in 20 words or fewer: (a) anomeric carbon (b) enantiomers (c) diastereomer (d) furanose (e) pyranose (f) epimers (g) aldose (h) ketose

20. (a) How many asymmetric carbons (chiral centers) does each of the anomers of glucose in the pyranose ring form structure have? (b) How many stereoisomers of the glucose are theoretically possible?

21. Identify all the epimeric pairs in the structures shown below.

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22. Describe the differences between a proteoglycan and a glycoprotein.

23. Describe the structure of a proteoglycan aggregate such as is found in the extracellular matrix.

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Answer Key 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23.

A D D D A B A A E B C B B C E D B

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