E. coli bacteria need the amino acid tryptophan to survive. When tryptophan is present in its growth medium, E. coli is able to ingest it. However, tryptophan is not always available in the E. coli’s environment. What are some questions you can ask regarding how E. coli might respond if tryptophan is not present in its growth medium? Form a hypothesis that you can test to answer one of your questions.
