Quiz 4 Key |
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1-4. Use these types of enzymes: (O) oxidoreductase; (H) hydrolase; (I) isomerase;
(T) transferase; (Y) lyase; (G) ligase.
O converts Fe2+ to Fe3+ |
G forms a bond using ATP to provide energy |
H breaks a bond by adding H2O to it |
Y adds a functional group to a C=C bond |
H synthesizes a bond by removing H2O |
Y removes a functional group, |
I rearranges the structure of a |
T transfers a functional group from one |
5-8. For exam 4 we will study the enzyme that catalyzes this reaction.

The enzyme requires the coenzymes FAD and TPP.
Use the letters from 1-4 as well as these: (S) substrate; (P) product;
(C) co-substrate coenzyme; (R) prosthetic coenzyme
O,Y,T one type of enzyme this could be |
R FAD |
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I,G,H one type of enzyme this could not be |
R TPP |
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S pyruvate |
C CoA-SH |
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P CO2 |
P AcCoA |
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C NAD+ |
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9-10. Underline the value for the least favored (least spontaneous) reaction and circle the most favored. |
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ΔG°′ = – 2,000 J/mol |
Keq = 137 |
Keq = 0.62 |
ΔG°′ = 13,000 J/mol |
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Keq = 137 |
ΔG°′ = 3,000 J/mol |
ΔG°′ = 3,000 J/mol |
Keq = 137 |
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9-10. Underline the value for the least favored (least spontaneous) reaction and circle the most favored. |
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Keq = 0.062 |
ΔG°′ = 3,000 J/mol |
ΔG°′ = - 20,000 J/mol |
Keq = 1.37 |
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ΔG°′ = 6,900 J/mol |
Keq = 0.298 = 0.30 |
Keq = 3200 |
ΔG°′ = –780 J/mol |
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Comment: I added the complementary values to make the choices clearer, but I didn't expect you to do any calculations. Instead I hoped that the answers would be fairly obvious. What was clear was that most students are more comfortable with ΔG than with Keq. Oh yes, also note the units.