Membrane Protein Functions

Membrane proteins carry out several core functions: transport of molecules across the membrane, receiving signals as receptors, catalyzing reactions as enzymes, anchoring the cell to the cytoskeleton and extracellular matrix, and acting as recognition markers. A diagram is the clearest way to show all of these roles at once.

Membrane proteins are broadly divided into integral (transmembrane) proteins that span the lipid bilayer and peripheral proteins attached to the membrane surface. By function they include transport, receptor, enzymatic, anchoring (attachment), and cell-recognition proteins, which a labeled figure can display side by side.

Transport proteins move ions and molecules across the plasma membrane that cannot cross the lipid bilayer on their own. Channel proteins form pores for passive diffusion, while carrier proteins change shape to shuttle substances, sometimes using energy for active transport against a concentration gradient.

Receptor proteins bind specific signaling molecules such as hormones or neurotransmitters on the outside of the cell and trigger a response inside, often by changing shape and activating intracellular pathways. They let the cell detect and react to its environment without the signal entering the cell.

Cell-recognition proteins, often glycoproteins with attached carbohydrate chains, act as identity markers on the cell surface. They let cells recognize one another, support immune identification of self versus foreign cells, and help cells bind together to form tissues.

You can generate a membrane protein functions diagram on SciFig: describe the functions you want to show in the lipid bilayer, and SciFig produces an editable figure. You can then relabel each protein type and export it for a textbook figure, lecture slide, or poster.