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Wednesday, May 5, 2010

Analyzing the global psyche with Google

{Query} [Google-Recommended Completion]

{How to}
tie a tie
lose weight fast
get pregnant
get a girl to like you
write a cover letter
write a resume
solve a rubix cube
make jello shots
make it in america

{How do I}
find my ip address
get a passport
know if im pregnant
get my work copyrighted
love thee
delete my facebook account
download youtube videos
delete my myspace
breathe lyrics

{What is}
my ip
my ip address
lady gaga's real name
a good credit score
the meaning of life
cinco de mayo

{My girlfriend and I}
have nothing to talk about
fight all the time
are growing apart
are having communication problems
have nothing in common
are on a break
are bored
always fight
are going to different colleges
broke up

{My boyfriend and I}
fight all the time
have nothing to talk about
are growing apart
are on a break
can't communicate
are fighting
are bored
fight a lot
always fight


The average internet user is most concerned about finding a mate, a complicated process which often involves ties, jello shots, and kissing.  To impress potential mates, the average internet user is: looking for a good job; traveling to other countries; losing weight; writing books; and solving Rubix cubes.  To avoid scaring off potential mates (and perhaps potential employers), the average internet user is considering closing their accounts on various social networking sites.  Perhaps the only thing the average internet user is as interested in finding as true love is their IP address.

Once they have found a mate, the average internet user is desperately unhappy.  Regardless, the average internet user proceeds to make babies (a poorly-understood process).

Monday, May 3, 2010

The Brewing Continues

Both fermenters are bubbling like crazy today; I don't have a rotameter hooked up, but I would guess that carbon dioxide production is peaking in excess of 100mL per minute.  Everything in the must is now suspended, buoyed by the bubbles rising from the yeast, which are now floating in a cloudy layer near the surface.

It's obvious enough that yeast produces a ton of carbon dioxide during anaerobic growth... but how?  Molecular oxygen is not present to act as the final electron acceptor in oxidative phosphorylation, so the TCA cycle (the source of the carbon dioxide produces by you right now) certainly isn't active.  For a closer look, we go to the basic (unbalanced) bioreaction stoichiometry:

C6H12O6 (sugar) + CH1.9O0.51N0.23 (protein) -> CH11.77O0.49N0.24 (biomass) + C2H6O (ethanol)

Most available protein is going to biomass (which has almost the exact same stoichiometric ratios as protein), along with some of the sugar.  Most of the sugar will go toward generating reducing equivalents (NADH) and energy carriers (ATP), in which it will be almost stoichiometrically converted to ethanol.  If you take a look at that stoichiometry:

C6H12O6 (sugar) -> C2H6O (ethanol)

Glucose on the left has a 1:1 C:O ratio, whereas ethanol has a 2:1 C:O ratio.  Carbon dioxide has a 1:2 C:O ratio, so this is a likely solution for closing the mass balance!  Of course, this is all nasty global inference, which should be left to systems biology (fake science).

What really happens?  Pyruvate decarboxylase (using thiamine pyrophosphate [pictured] in an acid-catalyzed reaction) hacks pyruvate into acetaldehyde and carbon dioxide.  The acetaldehyde is converted into ethoxide by reaction with NADH, and is then protonated to yield ethanol.  This is 'Ethanolic Fermentation'.

(Isn't mechanistic biochemistry so much more satisfying?)

Sunday, May 2, 2010

Let The Brewing Begin

Oh school - the more classes you've taken, the more doing well just comes down to going through the motions and taking the time.  Unfortunately, all of this fake learning has been keeping me from doing the stuff I really want to do.

I'm headed to Germany in two weeks, but I wanted to get one solid project going before I head out.  Fairly quick to set up with long wait times to product?  Brewing fits the bill perfectly.

I kind of feel like 'brewing' with store-bought malts is sort of a cop-out.  I'd rather go with something simple and straightforward, do it right (meaning without too much cheating), and expand upward as I get better at it.  There are many indications that mead was one of the first fermented beverages, even predating agriculture itself, so it seemed like the perfect place to start.

Setting everything up was very straightforward.
Follow this project's progress in my Brewing Notebook.