Q: Carrier proteins bind and carry the molecules across what cell structure?


Read this paragraph and choose the correct option from the provided answers:

Carrier proteins bind and carry the molecules across the cell membrane. These proteins bind a molecule on one side of the membrane, change shape as they carry the molecule across the membrane, and deposit the molecule on the other side of the membrane. Even though a protein is involved in both these methods of transport, neither method requires energy. Therefore these are still types of passive transport.

 Choices:

- nucleus

- cell wall

- plastid

- cell membrane


A:
cell membrane