Choose the statements that describe why the isomerization reaction is critical for the subsequent cleavage reaction that results in formation of two threeâcarbon sugars in the glycolytic pathway.
the carbon of a carbonyl group has a partial positive charge and can delocalize electrons to facilitate cleavage of the c-c bond. without the isomerization reaction, c-1 will be the carbonyl carbon and the c-c cleavage will occur between c-2 and c-3
breaking a c-c bond is energetically unfavorable and can only proceed if a functional group with electronegative atoms is adjacent to the cleavage site to stabilize the reaction intermediates
to cleave a c-c bond, a nucleophilic carbon attacks the adjacent electrophilic carbon. the isomerization reaction moves the carbonyl group to c-2 thus making it a nucleophile that can attack c-3 to generate two three-carbon sugars
the partial positive charge on the carbonyl carbon can stabilize the carbon radicals formed by the homolytic cleavage of the c-c bond in the six-carbon sugar. since the c-c cleavage occurs between c-3 and c-4 of the six-carbon sugar, the carbonyl group needs to be on c-2
cleavage of a c-c bond in the six-carbon sugar occurs via a decarboxylation reaction that requires a carbonyl group adjacent to cleavage site to stabilize the carbanion intermediate