Which statement best describes the role of the proteins in the cell membrane?

Which statement best describes the role of the proteins in the cell membrane?

• A. Help move molecules or aid in cell recognition
• B. Provide energy storage
• C. Form channels
• D. Store genetic information

Answer: (A)

Membrane proteins mainly handle transport and cell recognition. They are embedded in the lipid bilayer and create ways for substances to cross the membrane that would otherwise be blocked. Some proteins form channels that act like pores, letting specific ions or small molecules pass through quickly. Others function as carriers, grabbing a substance on one side, changing shape, and releasing it on the other side. In addition to moving material, many membrane proteins serve as markers—glycoproteins with carbohydrate tags—that help cells recognize each other and interact properly. This combination of moving substances and enabling recognition best describes what membrane proteins do. The other ideas aren’t general roles of membrane proteins: energy storage isn’t a primary function of these proteins, storing genetic information is the job of DNA in the nucleus, and forming channels is only one transport mechanism among broader transport and recognition activities.

Membrane proteins mainly handle transport and cell recognition. They are embedded in the lipid bilayer and create ways for substances to cross the membrane that would otherwise be blocked. Some proteins form channels that act like pores, letting specific ions or small molecules pass through quickly. Others function as carriers, grabbing a substance on one side, changing shape, and releasing it on the other side. In addition to moving material, many membrane proteins serve as markers—glycoproteins with carbohydrate tags—that help cells recognize each other and interact properly. This combination of moving substances and enabling recognition best describes what membrane proteins do. The other ideas aren’t general roles of membrane proteins: energy storage isn’t a primary function of these proteins, storing genetic information is the job of DNA in the nucleus, and forming channels is only one transport mechanism among broader transport and recognition activities.