Membrane proteins

Membrane proteins

1. Integral proteins: penetrate bilayer, may be "transmembrane" ( go through entire cell)

   • Rhodopsin: transmembrane protein, present in rod outer segments. contains: 7 alpha helix, straight chain areas on external and internal side, and retinal pigment ( retinaldehyde) stuck in the middle

2. Peripheral proteins: entirely outside, noncovalent, many on entire side. form fibrillar network that acts as "skeleton"

   • Enzymes
   • Transmit transmembrane signals
   • cell-to-cell recognition molecules

3. Lipid anchored proteins