quinta-feira, 19 de julho de 2012

Tatuagem - E. coli


quarta-feira, 11 de julho de 2012

Música sobre o citrato

Aqui fica uma música do Dr. Ahern (www.davincipress.com/metabmelodies.html), desta vez dedicada ao primeiro intermediário do ciclo de Krebs, o citrato. Foi inspirada na canção God Rest Ye Merry Gentlemen.

Citrate Sonata

Our fats and carbs get broken down
To acetyl CoA
Oxaloacetate combines
In cycles TCA
The product of reaction one
Oh, citrate is its name
Iso-citrate, the product that ensues
Atoms got moved
Isocitrate is the product of step two

An oxidation soon occurs
Reducing NAD
An alpha-ketoglutarate
Resulting from step three
From here we could make glutamate
That is, if there’s a need
Don’t forget that we lost a CO2
Yes it is true
In reaction three we lost a CO2

So what’s the point of all these steps?
Well, let me tell you, friend
We use electron carriers
In working towards our end
Of synthesizing ATP
(A metabolic trend)
Oxidize, and then oxidize some more
Here in step four
Ketoglutarate gets oxidized some more

The enzyme with cofactors five
Including TPP
Lipoate, FAD, CoA
And also NAD
A succinyl that’s on CoA
Is what gets made, you see
This reaction occurs so fav’rably
Don’t you agree?
It’s a good reaction energetically

With four more steps, we’re halfway there
So let me summarize
When CoA’s lost we see that GT-
P is synthesized
The succinate that is produced
Will soon get oxidized
FAD goes to FADH2
What did we do?
We made fumarate and FADH2

Add water ‘cross the double bond
And malate we create
With one last NAD we can
Then dehydrogenate
To give a final product of
Oxaloacetate
It’s removed, and this lowers Delta G
Oh yes, indeed
It’s through pulling that this last step can proceed
.