Which of the following reactions is not part of the pentose phosphate pathway?
A)
$\mathrm { C } _ { 5 } + \mathrm { C } _ { 5 } \stackrel { \text { Transketolase } } { ? } \mathrm { C } _ { 3 } + \mathrm { C } _ { 7 }$
B)
$\mathrm { C } _ { 4 } + \mathrm { C } _ { 5 } \stackrel { \text { Transketolase } } {? } \mathrm { C } _ { 3 } + \mathrm { C } _ { 6 }$
C)
$\mathrm { C } _ { 3 } + \mathrm { C } _ { 7 }\stackrel { \text { Transketolase } } {? } \mathrm { C } _ { 6 } + \mathrm { C } _ { 4 }$
D)
$\mathrm { C } _ { 5 } + \mathrm { C } _ { 6 } \stackrel { \text { Transketolase } } {? } \mathrm { C } _ { 2 } + \mathrm { C } _ { 9 }$

E) All of the above.

Question

Which of the following reactions is not part of the pentose phosphate pathway?
A)
$\mathrm { C } _ { 5 } + \mathrm { C } _ { 5 } \stackrel { \text { Transketolase } } { ? } \mathrm { C } _ { 3 } + \mathrm { C } _ { 7 }$ 
B)
$\mathrm { C } _ { 4 } + \mathrm { C } _ { 5 } \stackrel { \text { Transketolase } } {? } \mathrm { C } _ { 3 } + \mathrm { C } _ { 6 }$ 
C)
$\mathrm { C } _ { 3 } + \mathrm { C } _ { 7 }\stackrel { \text { Transketolase } } {? }  \mathrm { C } _ { 6 } + \mathrm { C } _ { 4 }$ 
D)
$\mathrm { C } _ { 5 } + \mathrm { C } _ { 6 } \stackrel { \text { Transketolase } } {? } \mathrm { C } _ { 2 } + \mathrm { C } _ { 9 }$

E) All of the above.

Quizplus · Accepted Answer

The reactions listed in options A, B, and C are typical of the types of rearrangements that occur in the pentose phosphate pathway, involving the transfer of carbon units between sugar molecules by the enzyme transketolase. Option D, however, describes a reaction that does not fit the pattern of carbon unit transfers typically seen in the pentose phosphate pathway, as there is no step that directly converts a 5-carbon and a 6-carbon molecule into a 2-carbon and a 9-carbon molecule within this pathway.

Which of the Following Reactions Is Not Part of the Pentose