Exam 21: Biomolecules: Carbohydrates

Using the following structure of D-talose as a guide,draw the structure for a-D-talopyranose.Label each ring substituent as axial or equatorial.

Aldohexoses may exist as furanoses or pyranoses.Aldopentoses also may exist as furanoses or pyranoses.

Draw the Fisher projection of L-mannose.

Instructions: Refer to D-iodose below to answer the following question(s). Refer to instructions.The Fischer projection for D-iodose (above)corresponds to which pyranose below?

Complete the equation for the following reaction.

Use the information below to answer the following questions. a) Which of the above represent an aldose? a. only 1 and 2 b. only 1 and 3 c. only 2 and 3 d. 1, 2 and 3 b) Which of the above would not be oxidized by an aqueous solution of Br2? a. only 1 b. only 2 c. only 3 d. all of these

Instructions: Refer to the monosaccharides below to answer the following question(s). -Refer to instructions.Assign R or S configuration to each chirality center in sorbose.

Instructions: Refer to the equilibrium below to answer the following question(s). Refer to instructions.The correct name for the cyclic structure is____.

Convert the following Fisher projections into tetrahedral representations.

Which reagent would be best suited for the transformation shown?

What is the relationship between D-erythrose and D-threose?

Instructions: Refer to the monosaccharides below to answer the following question(s). -Refer to instructions.Draw both chair conformations of the a-anomer of rhamnose in its pyranose form.Circle the more stable conformation.

Instructions: Refer to the sugars below to answer the following question(s).Choose the sugar that best fits each description.There is only one correct answer for each question,but sugars may be used more than once.Indicate each answer by the corresponding letter. -Refer to instructions._____ a dextrorotary hexose and ______ a levorototary tetrose.

How many D-ketotetroses could exist?

Instructions: Refer to the monosaccharides below to answer the following question(s).Classify each sugar by type;for example,glucose is an aldohexose. -Refer to instructions.Sorbose is ____________________.

If the following compound undergoes oxidation in the presence of the appropriate enzyme,draw the structure of the likely product.

Treatment with dilute NaOH can convert

Instructions: Refer to the monosaccharides below to answer the following question(s). -Refer to instructions.Provide the complete name for the a-anomer of rhamnose in its pyranose form.

Instructions: Consider the reaction below to answer the following question(s). -Refer to instructions.Place a triangle around the anomeric carbon in compound Q.

Instructions: Consider the reaction below to answer the following question(s). -Refer to instructions.Which anomer is the LEAST stable? Q or Z