Question

Which of the following statements on membrane transport is NOT correct:

A. To transport of solutes in the unfavorable direction across the membrane, pumps couple the process with either ATP hydrolysis, light absorption, electron transport, orother favorable transport process.

B. Dissolved gases like O2, CO2, or NO simply diffuse across a membrane bilayer

C. Hydrophilic molecules require assistance by membrane proteins to cross the membrane bilayer.

D. The rate of transport facilitated by transporters is faster, but less selective for solutes compared to channels.

E. The movement across the membrane that is facilitated by channels and transporters is always in the direction favorable for the transport (i.e., ΔGt < 0).

Answer 1

The transport through the channel proteins are faster than the transport through carrier proteins because the channel are just pores in the membrane and are unsaturable while the transporters get saturated upon binding of molecules slowing down the rate of transport.

So option D (not correct) is correct.