5. Valine adopts one lowest energy conformation. Threonine, however, has a special ability to adopt the analogous conformation and another stable conformation not seen with valine. (a) Using the template projection, draw the lowest-energy conformations of the natural amino acids valine and threonine. (b) Threonine also has a low-energy conformation with the hydroxyl group in the 180 position, which takes advantage of a hydrogen bond with the carboxyl carbonyl oxygen. Draw this conformation in template projection and highlight the hydrogen bond. (c) The phosphorylation of threonine activates a particular cellular pathway. Draw two lowenergy conformations of the phosphorylated threonine. ( Note: O-P bonds are long, which decreases the steric penalty of potential gauche interactions). (d) Drawing upon your knowledge of E2 reactions (antiperiplanar!!), propose a mechanism within a template projection for the novel enzyme eliminase that eliminates the phosphate group of phosphorylated threonine to yield only ONE alkene stereoisomer. Assume the enzyme contains a base (Enz-B:) capable of deprotonating phosphorylated threonine as necessary. phosphorylated threonine 5. Valine adopts one lowest energy conformation. Threonine, however, has a special ability to adopt the analogous conformation and another stable conformation not seen with valine. (a) Using the template projection, draw the lowest-energy conformations of the natural amino acids valine and threonine. (b) Threonine also has a low-energy conformation with the hydroxyl group in the 180 position, which takes advantage of a hydrogen bond with the carboxyl carbonyl oxygen. Draw this conformation in template projection and highlight the hydrogen bond. (c) The phosphorylation of threonine activates a particular cellular pathway. Draw two lowenergy conformations of the phosphorylated threonine. ( Note: O-P bonds are long, which decreases the steric penalty of potential gauche interactions). (d) Drawing upon your knowledge of E2 reactions (antiperiplanar!!), propose a mechanism within a template projection for the novel enzyme eliminase that eliminates the phosphate group of phosphorylated threonine to yield only ONE alkene stereoisomer. Assume the enzyme contains a base (Enz-B:) capable of deprotonating phosphorylated threonine as necessary. phosphorylated threonine