You are investigating the metabolism of glutamic acid in E coli, which enters the TCA cycle as a-Ketoglutarate following an initial transamination reaction.
a. If you radiolabel the a-carboxyl carbon atom, what fraction of the radioactivity will appear in CO2 during:
i. The conversion of glutamate to oxaloacetate?
ii. The cycling of OAA through the next cycle of the TCA cycle?
b. Indicate the labeling pattern of the following if the side chain carboxyl carbon of glutamate were labeled:
i. Initial OAA
ii. The a-Ketoglutarate produced in the next turn of the TCA cycle from the OAA labeled in b.i. above.