9. Carbohydrates

The sugar α-D-Mannose is a sweet-tasting sugar. β-D-Mannose, on the other hand, tastes bitter. A pure solution of α-D-mannose loses its sweet taste with time as it is converted into the β anomer. Draw the β anomer:

Draw the α-furanose and β-pyranose forms of D-ribose.

Indicate if the following pairs of sugars are enantiomers, anomers, epimers, or an aldose-ketose pair:

a) α-D-galactopyranose and β-D-galactopyranose. ____________________

b) D-glucose and D-mannose. ____________________

c) D-glucose and D-fructose. ____________________

d) α-D-glucopyranose and β-D-glucopyranose. ____________________

e) D-galactose and D-glucose. ____________________

f) α-D-mannopyranose and α-L-mannopyranose. ____________________