Cell membranes and membrane transport

Biological membranes

Rates of diffusion:
different types of molecules

Membrane ion concentrations at rest

Transport mechanisms

Examples of transport mechanisms

Simple diffusion

Facilitated diffusion

Distinguishing between simple and carrier mediated transport
Km= transporter affinity for substrate- lower the Km, the higher the affinity.

Facilitative glucose transporters:
The GLUT transporters

Structure of the human glucose transporter GLUT 1

Regulation of GLUT4 by insulin

Active transport

Primary active transport: how energy is harnessed through Na+/K+ ATPase

Na+/K+ ATPase as a drug target in the treatment of congestive heart failiure

Secondary active transport

When active transport is disrupted: how cholera toxin acts on lumen in the gut to cause huge electrolyte and fluid losses in the intestine

Role of Na+/glucose cotransporter in electrolyte replacement therapy for cholera