Enzyme Bio-Battery Runs on Ethanol

mpthompson writes "According to this article at New Scientist.com substantial progress is being made on enzyme-catalyzed ethanol based batteries to run cell phones and laptops. Such batteries promise to be cheaper, safer and less toxic than previously demonstrated methanol based fuel cells."

Comments

Re:The major problem of the next year may well be.

[Rich0]

I really wonder how do something as sensitive as enzyme withstand the working temperature of a computer

There is a whole industry based on developing crosslinked enzyme crystals which are useful in industrial applications as catalysts. The crystals are literally poured out of plastic bottles as a powder and many can function in organic solvents (which would completely denature ordinary enzymes). The cross-linking holds together the overall tertiary structure of the enzyme, and the enzyme tends to hang onto water where it needs it to maintain secondary structure.

I don't know exactly how thermally stable they are, but I imagine they can take quite a bit. While the technology probably hasn't been applied to the enzymes in question I imgaine that if the money was there it could be done.

Re:The major problem of the next year may well be.

[Sgt York]

The article was fairly scarce on details, but there are thermostable enzymes. We use some that are perfectly fine after sitting at 90+ degrees (C) for hours. These are from bugs that live in hot areas (geothermal vents), and therefore need thermostable enzymes. The most common example is the Taq polymerase used in PCR.

There are other enzymes that tolerate boiling, and other extreme conditions. They are inactive in the severe condition, but have such a stable tertiary structure that they snap right back when put into the proper environment again. Mammalian RNAses are notorious for this.

From the article, however, the restriction of the enzymes to these pockets may help. For those that don't know, enzymes have a structure like a ribbon (or several ribbons) that fold back on themselevs in a particular way. By thermodynamics, as you add heat, you add entropy and the ribbon moves around too much to stay in its functional orientation.

Keeping the enzyme in a small, restrictive pocket may restrict its random motion enough to help keep the ribbon from unfolding, allowing the enzyme to function at a higher temperature than it normally would.