Question

Reseforms week2 SUB Design Layout References A A A A Mailings Review View 41 5 ABCD AaBb C Het Oxaloacetate Aparate Aspartate -semaldehyde Homoserie Methionine 4 Isoleucine • Examine the branched pathway shown here for the synthesis of the amino acids aspartate, methionine, lysine, threonine, and Isoleucine . Scenario 1: The microbe is cultured in a medium containing aspartate and lysine but lacking methionine, threonine, and isoleucine. . Scenario 2: The microbe is cultured in a medium containing a rich Supply of all five amino acids. . For each of these two scenarios, answer the following questions: .a. Which portion(s) of the pathway would need to be shut down in this situation? .b. How might allosteric control be used to accomplish this? words English (United States

Answer 1

a) In case of scenario 1, Aspartate b-semialdehyde to Lysine pathway would need to be shut down. Because Lysine is present in media. Aspartate is also present in media but need not to shut down. Because amino acids lacking are synthesised from Aspartate.

In case of scenario 2, all pathways need to be shut down (as per given diagram). Because all five amino acids are present in media

b) Allosteric control means nonsubstate bind to site on enzyme other than active site and affect enzyme activity (usually inhibit).

In case of scenario 1, binding to any of three amino acids (methionine, threonine, isoleucine) to enzyme(s) which convert Aspartate b-semialdehyde to Lysine might control or inhibit lysine pathway.

In case of scenario 2, an amino acid could allosterically control other pathway. Thus inhibits whole pathways.