Exam 14: Biomolecules: Carbohydrates

Instructions: Refer to the equilibrium below to answer the following question(s). Refer to instructions. Which enantiomer of ribose is drawn, D or L, and is it the a or b anomer?

Which of the following could not form a pyranose?

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. _____ oxidizes to an optically inactive aldaric acid.

Instructions: Draw structures for the products you would expect to obtain from reaction of b-D-galactopyranose with the listed reagents. Be sure to include all relevant stereochemistry. b-D-galactopyranose Draw:

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 ____________________.

How many D-ketotetroses could exist?

Refer to the carbohydrate below to answer the following questions. a) Which carbon in the carbohyيate is the anomenc carbon? b) Doesthisrepresent an a or b-anomoer?

Instructions: Consider the reaction below to answer the following question(s). Refer to instructions. Compound Z is:

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.

Which reagent would be best suited for the transformation shown?

Use the information below to answer the following questions. 9) Which of the above represent an aldose? a. only 1 and b. only 1 mad 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 $Br_2$ ? a. only 1 b. only 2 c. only 3 d. all of these

Instructions: Refer to the equilibrium below to answer the following question(s). Refer to instructions. Classify ribose by carbonyl type and number of carbons.

Instructions: Draw structures for the products you would expect to obtain from reaction of b-D-galactopyranose with the listed reagents. Be sure to include all relevant stereochemistry. b-D-galactopyranose Draw:

Complete the equation for the following reaction.

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

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 ketose and _____ an aldose with two chirality centers

Draw an aldopentose with S,S,R stereochemistries at its carbons 2 through 4.

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

Instructions: Label each pair of stereoisomers as:

Describe the fundamental difference between the following classifications of carbohydrates. a. monosaccharide, disaccharide, polysaccharide b. simple sugar, complex sugar c. ketose, aldose d. furanose pyranose