Music about fermentation (2)

This is one more Christmas song (Rudolph the Red-Nosed Reindeer) that turned out into a song about biochemistry, this time about fermentation. Thank you Dr. Ahern (www.davincipress.com/metabmelodies.html)!


http://www.mediafire.com/?5afx4u8ed6uk80l

The Alcohol Song

Cells go through fermentation

When they’re out of NAD
Substrate phosphorylation’s
How they make their ATP

Cells are efficient makers ( . . .of)

Energy on which to live
With no electron takers
They need an alternative

Oh glycolysis would stop

Without NAD
Isn’t fermentation great?
For reducing pyruvate!

And if you might be thinking

“Man this isn’t cool at all”
Ask yourself when you’re drinking
“Where do we get alcohol?”

Music about fermentation

I like very much this music made by Dr. Ahern (www.davincipress.com/metabmelodies.html)... :)
It is about fermentation and is based in the famous Oh Susannah!

Here it is the link to download it:
http://www.mediafire.com/?zhbfbz91u70ca10

Oh, late last night I went to jog

when everything was still

I came upon a gravel road

a-windin’ up the hill

I don’t know why I did it but

I played a game with death

Ran up that hill in double time

And held in all my breath

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATP

‘bout half way up I felt the burn

My hip down to my knee

if only I had stayed awake

In biochemistry

then I’d have had a warning, but

regrets were just too late

I stood in pain - my body was

reducing pyruvate!

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATP

Well up came my professor who

was trailin’ close behind

he told me how fermenting was

a process most unkind

Oh ATP is energy

It’s keeping you alive

It’s mostly made by protons mov- ing

through the complex five

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATP

In making ATP a pro- ton gradient is key

to ADP’s phosphoryla- tion, oxidatively

Electrons pass through complex four

And oxygen, you know

picks up four more electrons and

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATP

I hope that you can clearly see

Exactly what I meant

That oxygen is needed for

The proton gra-di-ent

your muscles work in overdrive

And use up ATP

you might be breathin’ hard but lack sufficient energy

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATP

You’re in a heap o’ trouble and

this breath may be your last

if you can’t make some ATP

and NAD+ real fast

It’s lactate dehydrogenase

To save the day, you see

Turn pyruvate to lactate and

Produce more NAD+!

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATP

The NAD+’s important,

Are You gettin’ all of this?

it gets fed back into the pathway

of glycolysis”

It hit my ear, it was so clear

and all made sense to me

Although I had no oxygen

I still made ATP

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATP

For all he’d done I took my prof

to sit down for a drink

admitting that his lesson earlier

had made me think

I took a swig of ale

And grinning wide, I said with glee

Oh, fermentation hurts but all in all

It’s fine by me

Fermentation!

I need some NAD+

my cells are lackin’ oxygen

But using ATPmakes double H2O

Fermentation!

Alcoholic fermentation

The first reaction requires the presence of Mg2 + and the second reaction regenerates NAD+ from NADH (one molecule per molecule of pyruvate). As I mentioned in the post of lactic fermentation, this is the aim of fermentation, the regeneration of NAD+ so that glycolysis can continue to occur.
The pyruvate decarboxylase enzyme is normally present in yeast used in the manufacture of beverages and bread. The gasification of champagne and other alcoholic beverages, as well as the bubbles present in the bread crumbs are originated by the decarboxylation of pyruvate.

The alcoholic fermentation does not occur in our bodies. Bear in mind that when I say this, I am not saying that we can not metabolize ethanol, as this is an independent process of fermentation. What I am saying is that it is impossible for our body to convert glucose into ethanol.

Main bibliographic sources:

- Quintas A, Freire AP, Halpern MJ, Bioquímica - Organização Molecular da Vida, Lidel

- Nelson DL, Cox MM, Lehninger - Principles of Biochemistry, WH Freeman Publishers

Lactic fermentation

This reaction is clearly favored in the forward direction. In situations of hypoxia (intense muscular effort, for example), or absence of mitochondria, the cell is unable to regenerate NAD+ from NADH through the respiratory chain. It does so using the conversion of pyruvate to lactate, which consumes NADH and releases NAD+ release. It should be noted that the NAD+ is essential for glycolysis to continue to occur, thereby to obtain energy through the catabolism of sugars. Each molecule of pyruvate converted to lactate regenerates a molecule of NAD+. The lactate formed is sent through the bloodstream to the liver where it is converted to glucose in gluconeogenesis. The question that arises is: "So if you can recycle lactate, converting it back into glucose, why is the liver that has to do this and not the muscle, since it is the muscle that produces lactate? If so, the muscle could use directly the product of fermentation to restore the levels of metabolic fuel." In fact, at a first glance it may make sense to think in this way. However, the synthesis of glucose through gluconeogenesis is very expensive, in terms of energy, so that after an intense physical effort, it did not make sense that the muscle has to spend additional energy to synthesize glucose. Thus, the recovery of an intense effort includes not only the restoration of ATP levels in muscle but also an extra consumption of oxygen in the liver, necessary for the synthesis of ATP to be used in gluconeogenesis from lactate. In other words, after muscular efforts, is the liver that has to use lactate, allowing a faster and more efficient muscle recovery. This process is called the Cori cycle.

Dring anaerobic work the concentration of lactate in the muscle fibers can increase about 30 times and it is a commonplace to say that it is this accumulation of lactate ion which causes fatigue. However, the experimental evidence shows that although the concentration of lactate is directly related to the degree of fatigue it does not interfere with the the muscle contractile activity. Fatigue, muscle pain and cramping experienced after an intense physical effort are the result of an acidification caused by lactic acid in muscle (the pH can drop from 7 to 6.5 !!!). The pKa of lactic acid is about 4, which causes that at the cell pH (≈ 7) or plasma (≈ 7.4) occurs the dissociation of lactic acid to lactate + H+. This accumulation of H+ will interfere with the contractile capacity of muscle fibers and will also invade the synaptic cleft. Thus, the inability of the neuromuscular junction in relaying the nerve impulses to muscle fibers is due probably to a lower release of the chemical transmitter acetylcholine by nerve endings, due to acidification of the interstitial fluid and alteration of protein structures (acetylcholine receptors) by the action of H+. This system provides energy for physical activities that result in fatigue after about 60-120 seconds. It is therefore the primary metabolic process associated with activities such as running up to 400-800 m, swimming events of 100-200m, and also provides energy for high intensity moments in football, basketball, volleyball, tennis, among others. The common denominator of these activities is the support of high-intensity efforts lasting 1-2 minutes. Even the best trained athletes are unable to sprint for more than a minute. A highly competitive athlete needs about 30 minutes to recover from a 100m sprint. Some lactobacilli and streptococcus ferment lactose to lactic acid in milk. The ionization of lactic acid lowers the pH and causes denaturation of the casein (main milk protein) and other milk proteins. When this denaturation is controlled, and occurs in the right conditions, you get the yogurt or cheese.

 

In short, the fermentation is not used to get energy under anaerobic conditions (this misconception is very common ...). It serves to regenerate NAD+ so that glycolysis can continue to occur in the absence of O2, as glycolysis is the process that will produce ATP!

Main bibliographic sources:

- Quintas A, Freire AP, Halpern MJ, Bioquímica - Organização Molecular da Vida, Lidel

- Nelson DL, Cox MM, Lehninger - Principles of Biochemistry, WH Freeman Publishers

Cartoon about fermentation

Here is a cartoon about fermentation. :)