What are three functions of proteins in the cell membrane? Check all that apply. Receptors to bind to chemicals ☐ Provide nutrients for the cell Channels for ions to move through Cell division Adhere adjacent cells to each other
The Correct Answer and Explanation is :
The correct functions of proteins in the cell membrane are:
- Receptors to bind to chemicals ☑
- Channels for ions to move through ☑
- Adhere adjacent cells to each other ☑
Explanation (300 words)
Proteins in the cell membrane play vital roles in maintaining cellular function, communication, and structural integrity. Below is a detailed explanation of the selected functions:
- Receptors to Bind to Chemicals
Membrane proteins act as receptors to detect and bind specific molecules like hormones, neurotransmitters, and other signaling chemicals. These receptors trigger intracellular responses when they bind to their ligands. For example, insulin receptors on cell membranes help regulate glucose uptake. This receptor-ligand interaction is essential for processes such as cell communication, immune responses, and hormonal regulation. - Channels for Ions to Move Through
Proteins in the membrane form channels or pores that allow ions (e.g., Na⁺, K⁺, Ca²⁺, Cl⁻) to move across the lipid bilayer. These channels are selective and often gated, opening or closing in response to stimuli like voltage changes or chemical signals. Ion channels are crucial for maintaining the cell’s electrochemical gradient, transmitting nerve signals, and regulating muscle contraction. For example, voltage-gated sodium channels enable the conduction of action potentials in neurons. - Adhere Adjacent Cells to Each Other
Some membrane proteins serve as adhesion molecules, linking cells together to form tissues. These adhesion proteins, such as cadherins and integrins, provide structural support and maintain tissue integrity. They also mediate communication between cells and play roles in processes like wound healing and immune cell trafficking.
The excluded options are not valid functions of membrane proteins:
- “Provide nutrients for the cell” is incorrect, as membrane proteins facilitate nutrient transport but do not serve as nutrients themselves.
- “Cell division” involves other cellular components like the cytoskeleton and not directly membrane proteins.
Understanding these functions highlights the complexity and essential role of membrane proteins in cellular life.