Protein X can bind to either protein A or protein B to form a complex.The association constants are 108 M-1 (X with A)and 106 M-1 (X with B).Which statement is true?
A)In the presence of excess X,it takes fewer molecules of A than B to generate a given amount of complex.
B)The dissociation constant of the complex XA is higher than that of complex XB.
C)B must be a larger protein than A.
D)The values of the association constants indicate that both complexes XA and XB are very unstable in small cells like E.coli.

Question

Quizplus · Accepted Answer

The association constant (Ka) for X with A is 108 M-1, which is higher than the Ka for X with B (106 M-1). This indicates that X has a higher affinity for A than for B. Therefore, in the presence of excess X, it would take fewer molecules of A than B to generate a given amount of complex.

Protein X Can Bind to Either Protein a or Protein