Concentration of urea on one side (side A) of permeable membrane is 20 and on other side (side B) is 40. If concentration on side A is increased to 40, what will happen to rate of diffusion?
It will become double
It will become four times
It will be zero
It will be reduced four times
Ans. is 'c' i.e., It will be zero [Ref: Principles of medical physiology p. 71)This question, the concentration gradient is zero as both sides (A & B) have same concentration (40) of urea.Thus there is no diffusion + Rate of diffusion is zero.