Tuturial Carbs
BIOL 1362-CARBOHYDRATE TUTORIAL
1. List the names and give the Fisher projection formulae and functions of three (3) biologically important monosaccharides in the cell.
2. In each of the above structures, indicate the chiral centres using an *.
3. Choose two (2) of the above and carry out cyclisation to achieve furanose and pyranose ring structures.
4. In the ring structures drawn in three (3), indicate whether the structures are α or β.
5. How many chiral centres are present in D-fructose? Determine the number of possible stereo isomers.
6. Draw the Haworth projection formulae for trehalose, lactose and sucrose. Indicate whether any of the three would show mutarotation and briefly explain your reasoning.
7. Enzymes which hydrolyse sucrose are often given the trivial name, “invertase”. Suggest why this might be so.
8. What is the Maillard reaction that occurs between reducing sugars and proteins in the dry state?
9. (a) Glycogen, starch and cellulose are polymers of glucose. Suggest reasons why their structures are appropriate for their roles in nature.
(b) Why are the polymer forms of starch and glycogen utilized as storage forms of glucose by living cells rather than an equivalent amount of free glucose?
10. (a) Draw the structure of the trisaccharide:
D-mannose-,β (1,3)D-glucose-α (1,6) D-galactose using the Haworth projections.
D (b) Give the names of two (2) biologically important trisaccharides and list dietary sources.
E
F 11. Using Haworth or Fischer projection formulae of named sugars, explain the following
G terms: a) anomers b) epimers c) diastereoisomers
12. Outline the sorbitol-aldose reductase pathway. Why is this pathway more active in diabetic individuals than in healthy individuals?
1. List the names and give the Fisher projection formulae and functions of three (3) biologically important monosaccharides in the cell.
2. In each of the above structures, indicate the chiral centres using an *.
3. Choose two (2) of the above and carry out cyclisation to achieve furanose and pyranose ring structures.
4. In the ring structures drawn in three (3), indicate whether the structures are α or β.
5. How many chiral centres are present in D-fructose? Determine the number of possible stereo isomers.
6. Draw the Haworth projection formulae for trehalose, lactose and sucrose. Indicate whether any of the three would show mutarotation and briefly explain your reasoning.
7. Enzymes which hydrolyse sucrose are often given the trivial name, “invertase”. Suggest why this might be so.
8. What is the Maillard reaction that occurs between reducing sugars and proteins in the dry state?
9. (a) Glycogen, starch and cellulose are polymers of glucose. Suggest reasons why their structures are appropriate for their roles in nature.
(b) Why are the polymer forms of starch and glycogen utilized as storage forms of glucose by living cells rather than an equivalent amount of free glucose?
10. (a) Draw the structure of the trisaccharide:
D-mannose-,β (1,3)D-glucose-α (1,6) D-galactose using the Haworth projections.
D (b) Give the names of two (2) biologically important trisaccharides and list dietary sources.
E
F 11. Using Haworth or Fischer projection formulae of named sugars, explain the following
G terms: a) anomers b) epimers c) diastereoisomers
12. Outline the sorbitol-aldose reductase pathway. Why is this pathway more active in diabetic individuals than in healthy individuals?