You have isolated four different mutants unable to synthesize compound E required
for growth. You know that compounds A through D are involved in the biosynthetic
pathway that produces compound E, but you do not know the order in which they are
synthesized by a wild-type cell. You supplement the growth of each of the 4 mutants
with each compound and assay its ability to support growth. Using the data below,
construct a biochemical pathway indicating the order of the compounds and the step
where each mutation is acting. Explain how you arrived at the map.
A B C D E
1 − − − − +
2 − + + + +
3 − − + + +
4 − − + − +
First, in all mutations, E could not be synthesized. Therefore, E is the end product of the pathway.
For mutation 2, compound A is not affected, while B,C,D,E are affected. Therefore, A is in the ...
Biosynthetic pathways in mutations are examined.