28.
A:
Carrier proteins do not bind to the transported material while channel proteins do
B:
Carrier proteins are synthesised by free cytoplasmic ribosomes while channel proteins are synthesised on endoplasmic reticulum bound ribosomes
C:
Carrier proteins transport molecules down their electrochemical gradient while channel proteins transport molecules against the electrochemical gradient
D:
Carrier proteins can mediate active transport while channel proteins cannot
The answer is: D