Rate limiting step in facilitated diffusion?: (A) Availability of contranspo, (B) Conformational change in transpoer, (C) Synthesis of carrier protein, (D) Polarization of solute
Answer is B. Ans. is'b'i.e., Conformational change in transpoer(Ref: Essentials of membrane Biophysics p. 25I).The relative slowness of the rate constant for conformational change reorienting the Solute-unoccupied transpoer (Step-4) makes it the rate-limiting step in the process of facilitated diffusion.