1. (2 points) For the structures below, circle those that are D-glyceraldehyde and underline those that are L-glyceraldehdye.
2. (2 points) Write the structure of alpha-D-ribofuranose.
3. (3 points) D-mannose is the C-2 epimer of D-glucose. Write its structure in an open-chain form and in a beta-pyranose form using a Haworth projection.
4. (3 points) Write the structure of the sugar that would give the same aldaric acid (dicarboxylic acid) as D-ribose. Name this sugar. Is it a reducing sugar?
