Channels form pores through which molecules of appropriate size and charge can cross a membrane. By contrast, carrier proteins
A) actively transport molecules.
B) selectively bind the molecule to be transported, change configuration, and release it on the other side.
C) require ATP.
D) transport a molecule against its concentration gradient.

Question

Quizplus · Accepted Answer

Carrier proteins selectively bind the molecule to be transported, change configuration, and release it on the other side. This type of transport is known as facilitated diffusion and occurs down the concentration gradient without requiring energy input (such as ATP). Active transport, involving the use of ATP, is used to transport molecules against their concentration gradient.

Channels Form Pores Through Which Molecules of Appropriate Size and Charge