Egy fülbemászó dallam, egy ismert dal szövegének módosítása sokat segíthet a tanulásban. A példák a Molekuláris biológia anyag elsajátítását segítik, köszönet a dalok megtalálásáért Hrabák András tanár úrnak.
BETA-OXIDATION SONG
To ‘There is a Tavern in the Town’.
There is a pathway in the cell (in
the cell)
That metabolises well (awfully well)
Fatty acyl chains in a most effective way
To acetyl coenzyme A.
It’s called beta oxidation, and by way of explanation
In the mitochondrial matrix is the major part.
It starts however on the cytosolic side
With fatty acids coming from triglyceride
Activated in the thiokinase way
To thioester of CoA.
Acyl CoA can’t permeate (permeate)
The inner membrane to its fate (sad to state)
But a transferase now comes upon the scene
Making fatty acyl carnitine.
And there now is permeation, and a new transacylation
Generating acyl CoA in the matrix space.
We now begin upon an oxidation phase
With FAD-dependent dehydrogenase
(The flavoprotein is oxidised again
By ETF, thence by the chain).
Of two H atoms thus relieved (thus
relieved)
Desaturation’s been achieved (been achieved)
And as they came from the alpha:beta slot
Enoyl CoA’s what we’ve got.
And it’s in that same position we get aqueous addition
That is catalysed by enoyl hydratase
OH addition’s onto carbon number 3
Giving beta hydroxy acyl CoA
Which now proceeds upon its way.
Keto formation next we see (we see)
From beta-ol plus NAD (NAD)
The hydroxyacyl dehydrogenase
Prepares the way for thiolase
And, say, who would be a critic, of cleavage thiolytic
Of a simple beta keto thioester bond?
Coenzyme A is the attacking moiety
And acetyl CoA the product that’s set free,
So the common feature each such sequence shares
Is stripping carbons off in pairs.
An acyl CoA thus is left (thus is
left)
Of two-carbon fragment bereft (oh, bereft!)
Ready activated for another round
All citric acid cycle bound.
And if you perchance enquire, I’ll simply point out that that spiral
Has analogies to steps starting from succinate.*
Each turn of its can give you five times ATP
Apart from acetyl CoA that is set free.
Activation puts two squiggles up the spout
But just you think what you get out!
*Apparently, if this is not immediately apparent to you, just think about it!