Kings of energetics

By Joey Saavedra

Deep within the cell’s domain
Far minute to see
Kings of energetics reign
To fuel this life that be.

Unlike the kings of times forgot
Wrought they with strife and toil
The tsars within at conflict not
Need not the cell despoil.

For in this land the kings call home
Key are all who lead
Each involved, though not alone
As DNA decreed.

The verve within compels these kings
(And noble be their cause)
To power many different things
Commands of them few flaws.

Each must rule in tandem
Not all in equal measure
Their actions far from random
Exist they not for pleasure.

When movement becomes essential
Or as gradients are made
Energy is thus potential
For cell work to be conveyed.

Very little is free, you see
Less not thou live in pain
Demand always the Kings – their fee
For cell life to sustain.

True- most of what goes on inside
Though not the passive discourse
Is evidently well supplied
By an energy yielding source

This source we know today as such
We cannot understate
For synthesis is needed much
Adenosine Triphosphate

A molar mass of five-oh-seven
Grams per mole, indeed
ATP – this gift from heaven
Too large to store with greed.

This ubiquitous ingredient
Is thus made on demand
Be this, yes, expedient
Though tough to understand

Such regal clout the Kings do wield
And with little hesitation
Yet naught be the triphosphate yield
Without enzyme mediation

And so we begin our journey thus
Each pathway we shall chart
With open mind and little fuss
Let energetics start!

Part 1 – The Immediate Energy System

It so happens Adenosine Triphosphate
Is small in stored summation
And is enough to barely fuel a run
Of three-seconds in duration.

Thus, in order to resynthesize
That for which we need
The cell employs P.C.R
To satisfy our greed.

P.C.R – The cell’s first King
A known temporal buffer
Doth sacrifice a phosphate bond
So triphosphate need not suffer.

Short for Phosphocreatine
And larger in supply
A phosphate group is given such
Diphosphate can’t deny.

Occur this so within the cell
The cytosol indeed
So ATP kept constant to
Drive seconds more of need

Yet limited this king of ours
Since finite be his might
P.C.R reductions mean
Others must join the fight

And within the Glycolytic realm
Another king doth reign
Who is quick to act once is declared
Triphosphate’s on the wane.

Part 2 – Glycolysis

And so the Glycolytic King
With many an enzyme minion
Takes charge of energetics now
Still in cytosol dominion.

He promotes the oxidation
Of glucose in the cell
And without the need for oxygen
It’s a role he must excel

He firstly ‘traps’ the glucose
Adding phosphate to its main
Pledging fate to Glycolysis
For triphosphate to regain.

From Glucose-6-phosphate
To Pyruvate at the last
Enzyme mediated guile
Nine reactions – oh so fast!

There are three for whom the king doth hold
To account more than the rest
These minions of glycolysis
Must regulate by request

The first be Hexokinase
The second - P.F.K
And the third adds phosphate to PEP
King’s minions doth purvey

An energy investment
In the form of ATP
Is the primer of a couple steps
Those steps be one and three.

Here, some work is needed
To catalyze the change
Of F.6.P and glucose
A structure rearrange.

Soon after this investment
A repayment is conveyed
With gross Phosphorylation
Four triphosphates are re-made

Hence there is a yield
In net energy production
Of two triphosphates in this path
Of glycolysis seduction

But more central to this story
A task of emulation
Is reduction of the co-enzymes
Through dehydrogenation.

To continue degradation
Of the transformed glucose bonds
G3P must oxidize
And NAD responds.

In doing so, this co-enzyme
Can shuttle through its cargo
Towards the mitochondria
If Glycolysis be largo.

Though if the glycolytic rate
Exceeds the shuttle action
Recycle must the NAD
In LDH reaction.

A consequence of exercise
More so high intensity
The LDH reaction
Becomes the cell’s propensity

But in the resting state we know
The next king takes control
And through the oxidative paths
His rule we must extol.

Part 3 – Aerobic Metabolism (The Krebs Cycle)

Pyruvate sometimes has the chance
Of Decarboxylation
And with the help of carriers
Makes haste in translocation

From cytosol to powerhouse
Pyruvate’s fate is sealed
As PDH (in complex form)
Has power now to wield.

Coenzyme-A, thrown in the mix
With loss of C.O.2
What forms from this, indeed we know
May oxidize straight through

A.C.A combines with Ox
That’s ‘Oxaloacetate’
With Citrate Synth and H.2.O
Determining the rate

So, as we know Citrate is formed
Which undergoes conversion
In many steps defined by Krebs
A mitochon’ excursion

True, indeed, the realm before
Re-synthesis took place
So too, here, we see once more
Triphosphate show its face

The King of Krebs is granted much
In terms of redox fee
For coenzyme reduction
Is four-fold guarantee

Of these four dinucleotides
One, we know, is Flavin based
But all of them, now energized
Shuttle from the Krebs with haste

Part 4 – ETC

Our final King possess great
Skill and capability
A sovereign oxidative star
With dash and versatility

This be so, indeed, because
Chemiosmotic theory
Shows how hard it is to keep
The cell from feeling weary

The king’s domain, the ETC
(Electron Transport Chain)
Can so be found attached to the
Inner mito’ membrane

The coenzymes are oxidized
What of their precious load?
Well, to the mito’ complexes
Electrons are bestowed

The first among our minions
A dehydrogenase
Accepts a pair of ‘lectrons
And starts the enzyme craze.

In doing so, this complex
Pumps up into ‘the space’
Some protons from the matrix
With ‘fabulosos’ pace.

Next in line – Coenzyme Q
Or Co-Q-ten, if you prefer?
Taketh from the first minion
Electrons he can transfer.

He passes on his cargo
To he who next in line
Is known by most as cytochrome
Though B.C.1 is fine.

A friend and close companion
‘C’ quickly lends a hand
Another cytochrome, for sure
Electrons still remand.

And as, of course, was true before
Hydrogens are moved
Into the space where more are found
The gradient improved.

The final minion in this path
A complex cytochrome
Manufactures water from
Electrons in his home

Of course, he uses oxygen
And hydrogens as well
Essential be this Oxidaze
For safety of the cell.

The real magic is left to last
Since here the cell surprises
As ATP is born again
Unreal how it arises!

The proton concentration
In ‘the space’ described before
Is large, and so encourages
Much movement through the door.

We know this door as ‘Synthase’
And its job is simply this:
To add phosphate to ADP
Through chemiosmotic kiss.

The protons move from high to low
And synthase helps it through
And the energy that comes with it
Sticks phosphate on like glue!

Since all of this demands O.2
Then it truly is a fact
Re-synthesis of triphosphate
Is an oxidative act.

But what about the yield, you say?
What of triphosphate dictum?
Well, this amounts to thirty-six
When Glucose is victim!

And so our quest must come to end
As any journey should
The Kings of Energetics are
True forces for the good.

The cell would surely perish quick
Life would be denied
If ATP was hindered from
Being well supplied.