Question

Wild-type bacteria can grow on minimal medium. Four mutants that cannot grow on minimal medium but can grow on minimal medium supplemented with the nutrient “C” are isolated. It is suspected that metabolites A, B, and D are in the biochemical pathway for synthesis of C, so each mutant is tested for the ability to grow on minimal medium supplemented with these metabolites.
Mutant 1: can grow on minimal medium supplemented with A, but not B or D
Mutant 2: is unable to grow on minimal medium supplemented with A, B, or D
Mutant 3: is able to grow on minimal medium supplemented with B or A, but not D
Mutant 4: can grow on minimal medium supplemented with A, B, or D.

Which of the following is NOT consistent with this information?

A. Mutant 2 will cause a build up of metabolite D
B. Mutant 1 will cause a build up of metabolite B
C. Mutant 3 blocks the conversion of metabolite D → metabolite B
D. Mutant 2 blocks a step right before metabolite C.
E. Mutant 4 blocks a step before all 4 metabolites.

Answer 1

Mutant 1 will cause a build up of metabolite A