Question

Which one of the following process of transporting substances across a membrane does not involve a change in the shape of the transport protein?

• A. Active transport
• B. $N{a}^{+}-K^{+}$ pump
• C. Simple diffusion
• D. Facilitated diffusion

Answer 1

The correct option is C Simple diffusion

Both active transport and facilitated diffusion are mediated through membrane proteins, here channel proteins allow diffusion of solutes of appropriate size only, so in this size and shape of transport protein changes while simple diffusion does not require proteins for transportation.

So, the correct option is 'Simple diffusion'.