RESPIRATION: WHAT GOES IN, WHAT COMES OUT
by Arthur W. Siebens, Ph.D., Copyright 1999
(to the tune of Ob-la-Di Ob-la-Da by John Lennon and Paul McCartney)

Glúcose oxidátion has a lót1 of stéps, móst of which you dó not need to knów
Five májor parts are crítical so hóld on tíght and listen clósely because thís is how it góes:

1. Glycólysis tákes 6 carbon glúcose, bréaks it to 2 pýruvates with 3 (C's)
Makes 2 NADH's then through súbstrate lével phosphórylation mákes 2 ATP's

CHORUS
What goes ín/what comes óut-don't get bógged dówn, all those stéps will make your héad spín 'róund!

2. The pýruvate énters mitochóndriá (the matrix), from the cýtosol whére it just got máde
The múltienzyme cómplex chops off CO2, yields NADH and Acétyl CoÁ
3. Acétyl CoA énters the Krebs cýcle, adds 2 carbons to 4 (oxaloacetic acid) now you've got 6 (citric acid)
As it lóses 2 CO2's, 3 NADH's fórm, 1 FADH2 and an ÁTP 2 for kícks

CHORUS
What goes ín/what comes óut-don't get bógged dówn, all those stéps will make your héad spín 'róund!

4. The NADH (and FADH2) with 2 high énergy eléctrons, gíves them to the eléctron tránsport cháin
As they móve to oxygén making H2O 3, protons are púmped across the ínner mémbráne

5. Now you've gót a gradiént of prótons (chemical and electrical)-they wánt to go back tó the matríx
ATP sýnthase lets them ín, converts their énergý, makes ATP-its one of náture's gréatest trícks.

So oxidátion of NADH is cóupled to phósphorylátion of 3 ATP's
And suppórt for chemiosmósis cómes from uncóuplers like DNP (dinitrophenol) Yés, ít dóes!

They máke the inner membrane léaky-there's no (proton) grádient, phosphórylation's blócked
But glúcose oxidátion keeps húmming stróng, and the sécret to the cóupling ís unlócked!
Óxidative phósphorylátion's óne of evolútion's biggest cóups4
It mákes 90 percént of your ÁTP- so withóut it, in a féw minutes you're thróugh!

CHORUS
What goes ín/what comes óut-don't get bógged dówn, all those stéps will make your héad spín 'róund!
So breathe ín, then breathe óut-got that áll dówn? Réspirátion5 kéeps yóu 'róund!
So you gót thát áll dówn? Réspirátion5 kéeps you 'róund!

1 Accent marks (as in "lót") indicate accented syllables.
2 Through substrate level phosphorylation. "For kicks" reinforces the concept that this accounts for only 1 of the 12 ATP's ultimately resulting from each turn of the Kreb's cycle.
3 2 e - + 1/2O2 + 2H+ = H2O
4 The evolution of eukaryotes (with their mitochondria) from prokaryotes took roughly twice as long as the evolution of prokaryotes from non-living matter.
5Whole-body respiration in breathing provides oxygen for cellular respiration in mitochondria.