Question

What is the difference between a transport protein and a channel protein?

A. Transport proteins can only function via active transport.
B. Transport proteins are often used by many substrates while channel proteins are generally used by ions.
C. Channel proteins are often larger than transport proteins.
D. Transport proteins are often larger than channel proteins.
E. Transport proteins are simpler than channel proteins.

Answer 1

Channel proteins provide a passageway for ions to diffuse across the membrane, while carrier proteins bind to specific molecules and transport them by changing shape.

Step-by-step explanation:

Channel proteins provide an open channel or passageway through the cell membrane for molecules to move across. Many channel proteins allow the diffusion of ions. Ions are charged atoms. The charge makes it difficult to cross the cell membrane without assistance. Channel proteins are specific for the molecule they transport. For example, a sodium ion crosses the membrane through a channel protein specific for sodium ions.

On the other hand, carrier proteins are involved in passive and active transport. They bind to a specific ion, molecule, or group of substances and change shape to carry the bound molecule across the membrane. Carrier proteins are used to transport larger molecules that cannot pass through channels, such as amino acids and glucose.

In summary, the main difference between channel proteins and carrier proteins is that channel proteins provide a specific passageway for ions to diffuse across the membrane, while carrier proteins bind to specific molecules and transport them across the membrane by changing shape.