On Friday I went to see the recording of an episode of a new comedy quiz called "What on Earth?" It's a science based quiz, chaired by Marcus Brigstocke. A very enjoyable time was had, the highlight being a wonderful scientific joke:
- What's non-orientable and lives in the sea?
- Mobius Dick.
My sides were splitting. In search of other science-based mirth I found this
website which is chock full of scientific belly laughs: The mathematicians
among you will surely enjoy this rib-tickler:
- What do you get if you cross an elephant with a mountain climber.
- You can't do that. A mountain climber is a scalar.
Or How about this biochemical funny that will have them rolling in the aisles
"A bloke walks into a pub, and asks for a pint of Adenosinetriphosphate.
The barman says "That'll be 80p please!" (ATP geddit?)
All of this reminded me of a book that is still available called the
Biochemist's songbook, not something that I bought along with Stryer's
Biochemistry or Selkurt's Physiology. But here is one set of lyrics
to be sung to the tune of the British Grenadiers:
In Praise of GlycolysisSome pathways lead to glory, like Hatch and Slack and Knoop,
Utter, Calvin, Cori --- a most distinguished group,
But of all of nature's pathways, we sing the praise today
Of Embden, Meyerhof, Parnas --- the glycolytic pathway.
Glucose, by hexokinase is turned to G6P
(You might use glucokinase, you must use ATP)
And, note, glycogenolysis (when stores are in the cell)
Gives G1P which then mutates to G6P as well.
The moiety of glucose, in the succeeding phase
Is transferred to a ketose by an isomerase
Phosphofructokinase now, acts on that F6P;
Fructose 1,6 bisphosphate is the product that's set free.
The kinase is affected quite complicatedly
And as you'll have suspected it uses ATP;
FBP by aldolase is split reversibly
To phosphoglyceraldehyde, also DHAP.
The former and the latter can each equilibrate ---
It really doesn't matter for metabolic fate ---
So follow PG aldehyde and double what you see,
You'll get the total balance sheet for a hexose moiety.
There's now a novel facet, for NAD's reduced
But carboxylic acid is not what is produced,
Delta-G's substantial, and energy's conserved
(For otherwise the pathway would, quite frankly, be absurd).
The complex oxidation of PG aldehyde
Gives by phosphorylation an acid anhydride,
And that bisphosphoglycerate reacts with ADP
The kinase making ATP, of course reversibly.
The product's composition, 3-phosphoglycerate
From 3 to 2 position can readily mutate
And now 2-phosphoglycerate does something rather strange ---
Electrons on C2 and 3 proceed to rearrange.
The redox-dehydration, catalyzed by enolase
Gives PEP formation and bond energy raise
So phosphoenol pyruvate reacts with ADP
The kinase making ATP, but not reversibly.
In anaerobiosis, pyruvate's not the end;
The problem we suppose is not hard to comprehend;
The dehydrogenation to phosphoglycerate
Would grind to halt if NAD could not regenrate.
The answer is quite subtle, pyruvate is reduced,
Instead of glycerol shuttle, lactate is produced;
Lactate dehydrogenase performs that noble feat,
NADH is oxidized, the pathway is complete.
The balance sheet you'll see shows transfer of energy,
Two ATP's from glucose and three from G1P.
That's good, but oh to use the way where pyruvate's reduced
With decarboxylation first, the ethanol produced!
The theme for this week's 
