membrane proteins

what are the two components of phospholipids?

• hydrophobic interior (fatty acid chains)

• hydrophilic exterior (polar heads)

what are the three different types of membrane protein?

• integral membrane protein

• transmembrane protein

• peripheral protein

describe the structure of an integral membrane protein

• hydrophobic domain embedded within hydrophobic core of bilayer, interaction with lipid tails

• hydrophilic domains exposed to aqueous surroundings

describe the structure of a transmembrane protein

• spans entire bilayer

• hydrophobic domain traverses core of membrane

• hydrophilic domains extend to interact with aqueous environment (cytosol + extracellular)

• act as transporters, ion channels…

describe the structure of a peripheral protein

• does not penetrate into hydrophobic core

• associates with membrane surface via ionic interactions with phospholipid heads

• predominantly hydrophilic surface