THOSE MAGIC MEMBRANES
(Short version - the one recorded)
by Arthur W. Siebens, Ph.D., Copyright 1995
(to the tune of "La Bamba" by Richie Valens and "Twist and Shout," by Medley and Russell)

How do things get into cells?
How do things get out?
Transport across cell membranes
Is what this song's about.

Diffusion, osmosis
Active transport, too.
To make your cells and organs work right
The right solutes must get through.

CHORUS
Oh, those magic membranes
In each and every cell
Differences between solutes may be small
But membrane transporters can tell.

Oh those magic membranes!

They let the good stuff in
Get the bad stuff out
Through transporters made of protein
There's lots of different routes.

Membranes are mainly made of lipid
Most solutes can't penetrate
Proteins transport specific solutes
Many change their shape (conformational state).

Facilitated diffusion
(From) high concentration to low.
In cotransport a solute going "downhill"
Moves another "uphill" as it goes (secondary active transport).

There's also (primary) active transport
And that takes energy
Solutes are moved uphill
Energy from ATP.

CHORUS

If solutes can't cross a membrane
But water can diffuse
It will cross 'til equilibrium (the water concentration is the same)
Osmosis is when water moves (across cell membranes).

CHORUS

Oh those magic membranes! Yeah!