Question

a)Imagine that a cell has 1000 surface receptors for a particular ligand. Imagine also that 15% of the above receptors need to bind the ligand to achieve maximal response. What concentration of ligand is required to achieve this maximal response? Report your answer in terms of picomolar (pM) concentration to the nearest tenth of a unit. Assume the Kd for the ligand is 1.0 x 10-10 M.

b)Consider the information in the previous problem, but this time imagine that the number of cell-surface receptors decreased from 1000 to 200. What ligand concentration would now be needed to elicit the maximal response? Report your answer in terms of picomolar (pM) concentration to the nearest ones. Hint: the number of receptors that need to be bound to elicit the maximal response is the same as in the previous problem.

Answer 1