Integral proteins

Definition

Integral proteins are embedded within the lipid bilayer of cell membranes and can span across the membrane or be attached to one side. They play crucial roles in various cellular functions such as transport, signal transduction, and maintaining cell structure.

5 Must Know Facts For Your Next Test

1. Integral proteins can function as channels or transporters to move molecules across the cell membrane.
2. They often have hydrophobic regions that interact with the lipid bilayer and hydrophilic regions that protrude into the aqueous environment inside or outside the cell.
3. Integral proteins are typically classified as transmembrane proteins if they span the entire membrane.
4. The removal of integral proteins generally requires detergents because of their strong association with the lipid bilayer.
5. Integral proteins can participate in cell signaling by acting as receptors for hormones and other signaling molecules.

Review Questions

• What structural feature allows integral proteins to embed within the lipid bilayer?
• How do integral proteins contribute to cellular transport?
• Why are detergents often required to isolate integral proteins from membranes?

Related terms

Peripheral Proteins: Proteins that are loosely attached to the outer or inner surface of the plasma membrane.

Lipid Bilayer: A double layer of phospholipids that forms the core structure of all cell membranes.

Transmembrane Proteins: A type of integral protein that spans across the entire lipid bilayer.