Chem 30B          April 19, 2004         Name ________________________

2nd exam        70 min.                                        please print

102 points     Points are in the left margin, e.g., [6]    Seager, Chpts 5-7

 

Some questions have more than one correct answer. Donšt crowd your answers. Use the back if necessary.

 

1. Draw one structure for each description.

 

[5]  a. the organic product of the hydrolysis of acetamide

 

 

[5] b. the dimethylester of phosphoric acid

 

 

[5]   c. a Fisher projection of an amine with formula C4 H11NO  and 1 chiral carbon

 

many others OK

[5] d. alpha-D-galactose

 

 

0
  1. Fill in the blanks.

 [2]  a. Neurotransmitters in our bodies usually contain which functional group?

       AMINE                .

[3]   b. In terms of chemical reactions, the most important difference between an amine nitrogen and an amide nitrogen is    .amine is basic and amide is not.

[3]   c.  Lactose consists of galactose    bonded to glucose   by a

 glycoside or galactoside or beta (1ŕ4) link.

[2]   d. A hemiacetal is always in equilibrium with an  aldehyde  and an

alcohol .

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3. [5] Draw the structure of N,N-dimethylbenzamide

 

 

 

4. a. Draw the structure of an  L-aldotetrose.   b.  Draw the structure of its enantiomer. 

 c. Draw the structure of one of its diastereomers. d. Is this diastereomer L or D?

COULD BE EITHER  [2]

a. L-aldotetrose

 [4]

b. enantiomer

 [4]

c. diastereomer

            L-

 

5. a. [4] In the following compound circle and label all of the acidic sites and all of the basic sites.  

    b. [3] Draw carefully placed arrows to show each point in the compound that can hydrogen bond to water.

    c. [3]  Circle and name three (3) of its functional groups.                         


5. [8] a. Describe the specific chemical difference between cellulose and starch. Draw chemical structures to assist your description.

 

SEE TEXT

 

b. [4] In our bodies would the same enzyme be  able to break down both cellulose and starch?  _____   Explain your answer.

   No

 

6. Draw the structure of the major organic  products of each of the following reactions.

a. [5]

 

 

b. [5]

 

 

 

 

 

7. Benzoic acid is

                     

 

This question is based on a class demo!

 

 

 

 

a. [3] Will benzoic acid be soluble in cold water?

        yes  X no  Explain

 

ONLY SLIGHTLY

b. [3] Will benzoic acid be soluble in dilute acid ?

     yes  X no  Explain

 

No effect of acid on acid so same as water

c. [3] Will benzoic acid be soluble in dilute base ?

    X yes   no  Explain

 

 

Base converts acid to benzoate ion which is very hydrophilic

 

 

 

 

 

 

9.a. [6]   Draw a clear structural formula of any glycoside.

 

 

b. [6]  Will the compound you drew be reducing or nonreducing. Explain why.

 

 

All glycosides have at least one non reducing ring.

 

 

 

 

 

 

 

 

 

 

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