Cell Membranes

Cell Membrane Views

Phospholipid Molecule

Hydrophilic and Hydrophobic Molecules interacting differently with water

Wedge-shaped lipids form micelles Cylinder-shaped lipids form bilayers

Spontaneous sealing of phospholipid bilayer

Liposomes

Phospholipid mobility

Cis-double bonds affect packing

Cholesterol glycolipids

Function of Cholesterol

Phospholipid types

Microdomains on plasma membrane Lipid rafts Choresterol sphingolipids

Asymmetrical distribution of phospholipids and glycolipids

Phospholipids in cell signaling

Phospholipase Cleavage sites

Glycolipids

Membrane Proteins

Membrane Proteins

Fatty acid chain or prenyl group modifications

Hydropathy Plots

B-barrel membrane proteins

Membrane proteins are glycosylated

A detergent micelle

Solubilize membrane proteins with detergent

Detergents

Mild detergent for the solubilizing, purification, and reconstitution of membrane protein functions

SEM image of red blood cells

The preparation of red blood cell membranes

15 major membrane proteins in red blood cells

Membrane proteins are diffusable

Proteins restrictions

Protein distributions in a guinea pig sperm cell

4 ways of protein restrictions

Carbohydrate layer (Glycocalyx) on the cell surface

Diagram of glycocalyx

Summary Phospholipids, cholesterol, glycolipids for membrane Asymmetric, inner and outer monolayer subcompartments and lipid functions in cell signaling membrane proteins and their anchoring models diffusion, distribution glycocalyx, proteoglycan

Membrane Transport of Small Molecules and the Electrical Properties of Membranes

Permeability of plasma membrane

Carrier Protein and Channel Protein

Transportation Models

Electrochemical Gradient

Ionophores

Conformational change of a carrier protein

Kinetics of simple and carrier-mediated diffusions

3 ways of driving active transportation

3 types of carrier-mediated transport

Coupled transportation of glucose and Na+

Transcellular transport

Na+-K+ Pump, ATPase

Cycles of Na+-K+ Pump

Functions of Na+-K+ Pump

ABC transporter 2 ATP-binding cassette domains

A typical Ion Channel

The gating of Ion Channels

The Structure of bacterial K+ channel

Gating Model of K+ channel

Summary Membrane transportation, carrier protein, channel protein Active transportation, passive transportation ATPases, Na+-K+ Pump Gating mechanisms of Ion Channels, K+ channel selectivity