Chapter 11 - Phospholipids and Membranes

how does cholesterol impact fluidity?

the more cholesterol, the less fluid

how does tail length impact fluidity?

the longer the tail, the less fluid

aquaporins

water channels within a membrane

membrane receptors

bind to signaling molecules

membrane carriers

bind to substances to move them across the membrane

membrane gated channels

channels that can open and close

membrane channels

a “pore” with a selective passageway

integral membrane proteins

membranes embedded in the membrane, amphipathic

peripheral membrane proteins

proteins which lay along the membrane

what influences the membrane’s fluidity?

temperature, degree of saturation of fatty acid tails, tail length, presence of cholesterol

leaflet

one side of the phospholipid bilayer

phospholipid bilayer

heads face opposite directions (polar + hydrophilic), tails face the same direction (nonpolar + hydrophobic), has a hydrophobic core

amphipathic

when a substance has both polar and nonpolar regions

the 3 mains functions of plasma membranes

isolate the interior cell parts from the outer parts, regulate the passage of materials, and mediate cell-cell interactions

plasma membrane

the outer surface of a cell, mostly made of phospholipids, are amphipathic