Question

The presence of a negative allosteric effector on an allosteric protein would: a. cause a shift to the left in the sigmoidal curve. b. increase the number of R conformations. c. decrease the cooperativity of the substrate. d. raise the apparent value of the equilibrium constant, L. e. increase the likelihood of the binding of S.

Answer 1

Answer:

d. raise the apparent value of the equilibrium constant, L.

Explanation:

Allosteric regulation is a type of regulation of an enzyme by binding an effector molecule at a site other than the protein's active site (i.e., the allosteric site). The equilibrium constant (L) refers to the transition between two forms of an allosteric protein in absence of a ligand. The properties of allosteric enzymes are explained by conformational changes associated with a low-affinity tense (T) state, or a high-affinity relaxed (R) state. Negative allosteric effectors are molecules that bind to the allosteric site on an enzyme in order to decrease its activity, thereby leading the enzyme to a low activity T state and thus increasing the value of the equilibrium constant.