Which proteins help materials cross the membrane?

Which proteins help materials cross the membrane?

• A. Channel proteins
• B. Enzymes
• C. Transport proteins
• D. Receptors

Answer: (C)

Membrane movement of substances is handled by proteins that specifically facilitate crossing the lipid bilayer. These transport proteins bind or form passageways for specific molecules and ions, allowing them to move across the membrane either passively down their concentration or electrochemical gradient, or actively by using cellular energy to move them against the gradient. This makes transport proteins the best fit because they are the broad class of proteins dedicated to transporting materials across membranes, including channel proteins that create pores and carrier/pump proteins that shuttle substances through conformational changes or energy-driven steps. In contrast, enzymes catalyze chemical reactions rather than transport substances across membranes, and receptors bind signaling molecules to elicit responses rather than move materials across the membrane.

Membrane movement of substances is handled by proteins that specifically facilitate crossing the lipid bilayer. These transport proteins bind or form passageways for specific molecules and ions, allowing them to move across the membrane either passively down their concentration or electrochemical gradient, or actively by using cellular energy to move them against the gradient. This makes transport proteins the best fit because they are the broad class of proteins dedicated to transporting materials across membranes, including channel proteins that create pores and carrier/pump proteins that shuttle substances through conformational changes or energy-driven steps. In contrast, enzymes catalyze chemical reactions rather than transport substances across membranes, and receptors bind signaling molecules to elicit responses rather than move materials across the membrane.