Problem Set #5: Carbohydrates

1) Draw Haworth Structures for the following:

2) Name the following:
 


 
 

3) Draw a Haworth projection for the disaccharide gentibiose, given the following information: 1) It is a dimer of glucose.2) The glycosidic linkage is b(1->6) 3).   The anomeric carbon not involved in the glycosidic linkage is in the a configuration.

4) How does chitin differ from cellulose in structure and function?

5) How does glycogen differ from starch in structure and function?

6) Hexokinase is an enzyme that catalyzes the transfer of a phosphoryl group from ATP to glucose, fructose, or mannose, forming ADP and glucose 6-phosphate, fructose 6-phosphate, and mannose 6-phosphate, respectively. N-acetylglucosamine is a competitive inhibitor of hexokinase-catalyzed phosphorylation of all of these sugars.

7) Using the values for the standard free energies given in the attached table, determine whether each of the following reactions will proceed spontaneously in the direction written, under standard conditions: 8) The standard free energy change for the reaction: Arginine + ATP ---> Phoshoarginine + Pi

is +0.4 kcal mol-1. From this information and that in Table 11.3, calculate te change in standard free energy for the reaction:

Standard Free Energies of Hydrolysis for selected compounds:
 
Compound
DGo' (kcal/mol) 
DGo' (kJ/mol) 
Phosphoenolpyruvate
-14.8
-62
Carbamoyl Phosphate
-12.3
-52
1,3 Bis phosphoglycerate
-11.7
-49
Creatine Phosphate 
-10.3
-43
Pyrophosphate (PPi
-8.0
-33
ATP (to ADP)
-7.3
-30
Glucose 1-phosphate
-5.0
-21
Glucose 3-phosphate
-3.3
-14
Glycerol 3-phosphate 
-2.2
-9



Solutions to Problem Set #5:
 
Problem #1

Problem #2

Problem #3

Problem #4

Problem #5

Problem #6

Problem #7

Problem *8