What I meant was that regardless of the time taken if a given protein transports the same amount in either direction say 1 glucose and the transport protein can not change its cofiguration back without transporting in the reverse direction how can concentration on either side ever change Ex I have 10 particles outside 5 inside and 1 protein whenever 1 goes in this changes to 9 outside 6 inside but can never get to 8 outside 7 inside because the protein s substrate binding spot is now inside which means it can not bind a new particle from the outside without first transporting a molecule from the inside back out turning it back to 10 out 5 in clawx