Name ______Chem 21B

Carbohydrates practice problems

1) The form of fructose found in the disaccharide sucrose is which of the following? 1) A) a 5-membered cyclic hemiacetal. B) a 5-membered cyclic hemiketal. C) a 6-membered cyclic hemiacetal. D) a 6-membered cyclic hemiketal.

2) Define the term epimers and give two examples of epimers.

3) D-glucose and D-galactose differ in their stereochemistry at which carbon? 3) A) C1 B) C2 C) C3 D) C4 E) C5 F) C6

4) Which carbon is the anomeric carbon of glucose? 4) A) C1 B) C2 C) C3 D) C4 E) C6 F) C6

5) Which sugar is NOT a reducing sugar? 5) A) glucose B) fructose C) galactose D) maltose E) sucrose

6) Which of the following contains ΅-1,6-branches? 6) A) amylose B) glycogen C) cellulose D) sucrose E) maltose

1 7) Write the types of glycosidic bonds found in each of the following carbohydrates?

a) maltose

b) lactose

c) glycogen

d) chitin

e) amylopectin

f) cellulose

g) sucrose

8) Draw the structure of the product which results when D-ribose is treated with an oxidizing agent such as bromine water.

9) Draw the structures of all possible tetroses and name those that you can.

2 10) Draw the structures of all possible aldopentoses and name those that you can.

11) Draw the structures of all possible aldohexoses and name those that you can.

3 12) Draw the structures of maltose, lactose and sucrose. Label the location and type of glycosidic bond and provide a systematic name for each disaccharide.

13) a) Draw the structures of glycogen and cellulose. Label the location and types of all glcosidic bonds.

b) What impact does the the type of glycosidic bond have on the structures of glycogen and cellulose?

4 14) ONLY IF YOU'RE INTERESTED: List the aldohexoses described by the mnemonic "All altruists gladly make gum in gallon tanks."

15) ONLY IF YOU'RE INTERESTED: List the aldopentoses described by the mnemonic "Ribs are extra lean."

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