CHEM 120 Exam 3 KEY

CHEM 120 (Hamann) Exam 3 Name: ,
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Part I /60
Total of 124 exam points, adjusted to 100 course points.
ADJUSTED SCORE:
Part II /24

Please do the following steps carefully. Part III /40

Part I: Multiple Choice (3 points each, 60 pts total, No guessing correction, so answer ALL questions)
Note, only questions that are marked as such might have multiple correct answers.


E 1. Which of the following aldopentoses is the sugar in RNA?




D 2. Which of the following polysaccharides contains -1,4-glycoside linkages? Mark all that apply
a) amylose
b) amylopectin
c) glycogen
d) cellulose


A, D 3. Which of the following polysaccharides are unbranched? Mark all that apply
a) amylose
b) amylopectin
c) glycogen
d) cellulose


Use the following choices to answer questions 4-6.
CH2OH
CH2OH
CH2OH CH2OH CH2OH O
O OH
O O O
OH OH
OH OH OH OH HO
CH2OH OH O
HO O O
O
OH CH2OH CH2OH
D CH2OH
E HO
O
OH OH HO O OH HOCH2
OH HO O O
A OH O
HO
HO B C
OH OH OH
CH2OH
OH O
OH OH
OH OH

C 4. Which one of these structures is lactose?
E 5. Which one of these structures is sucrose?
A 6. Which one of these structures is maltose?

, E 7. For tertiary protein structures, the most important force is
A) disulfides that lock the structure in place
B) hydrophobic interactions
C) hydrogen bonding
D) hydrogen bonds made by the peptide backbone
E) All of the above are important and can make significant contributions

E 8. Enzymes can be slowed down or stopped by which of the following mechanisms.
A) Competitive inhibition
B) Covalent modification
C) Allosteric inhibition
D) Irreversible inhibition
E) All of the above

Use the following choices to classify the enzymatic reaction shown in questions 24-27.
A) a transferase
B) a lyase
C) an isomerase
D) a hydrolase
E) a ligase
AB) an oxidoreductase (bubble in both letters for this answer)




D 9.




AB 10.




A 11.




B 12.