Draw a hypothetical metabolic pathway composed of five substrates, five enzymes, and a product called Biological Sciazine. Number the substrates 1-5, and label the enzymes A-E, in order. (For instance, enzyme A catalyzes the reaction between substrates 1 and 2)

a. Suppose a mutation made the gene for enzyme C nonfunctional. What molecule would accumulate in the affected cells?

b. Suppose some individuals can survive if given substrate 5 in the diet, but they die if given substrates 1, 2, 3, and 4. Which enzyme pathway is affected by this mutation?