MolBiol Carnival #10: Assays, cyanobacteria and metabolism regulation

Welcome to the 10th edition of the MolBiol Carnival!

Apologies for the delay – am behind on pretty much everything and frantically trying to tie up loose ends of my degree, fun times. Also, it's kinda awkward to write up a carnival post with only THREE submissions – you guys really need to submit more and/or write more MolBiol posts!

It seems molecular biology doesn't get blogged about specifically as much as evolution and diversity – perhaps because molecular biologists are usually busy troubleshooting their PCRs and RNA work for weeks on end, and have little time left over to write. In fact, judging from recent woes experienced by some of my lab buddies, I'm beginning to doubt the existence of RNA and believe it may all be a giant elaborate hoax invented to enslave more grad students. Have any of you ever *seen* RNA? That's what I thought...

This month we have a very biochemical (post-translational, if you will) MolBiol Carnival featuring enzyme spec, cyanobacterial biofuel precursors and some sweet diastereomer metabolism regulation.

Enzyme Assay
Christopher Dieni at BitesizeBio has a nice write-up on measuring enzyme kinetics using UV spectrophotometry, complete with procedure, tips and troubleshooting – the kind of thing you wish accompanied every assay you've been assaulted by. Not being anything close to a biochemist, I had no idea you could actually observe enzyme action using something as simple as a spec, so this is quite cool!

Cyanobacteria and biofuel production
With growing concerns with using land plants for biofuels (for one thing, kind of odd to use food to power cars when not everyone has enough of it...), increasing attention has been turned towards algae eukaryotic and not. For one thing, algae are already quite good at photosynthesising and are vastly more abundant than plants, and arguably have the largest contribution to global photosynthesis – not surprising given the earth's surface is 70% ocean. Michael Scott Long at a NASW.org blog explains recent developments in genetic engineering and domestication of cyanobacteria for fatty acid production.

Diastereomers and regulation of metabolism
Stereoisomers are the beginning chemistry student's worst nightmare – they're so similar and easy to mix up, particularly if you're like me and can't tell left from right to begin with. However, a bacterium (rather, its enzymes) would have little trouble with the stereochemistry portion of a intro biochem class – to them, stereoisomers are day and night (and other things). Glucose and galactose are 'close enough' to each other for a biochem student, but a flipped arrangement at just a single stereocentre is enough to require a whole new set of enzymes and drastic changes in the pathway. E.coli prefers glucose, but can also process galactose (compromising its growth rate) by embellishing its metabolic pathways a little – the products of galactose digestion are sent to the tricarboxylic acid cycle via the glycoxylate shunt. Becky Ward at It Takes 30 discusses how sugar type availability affects the transcriptional regulation of this glycoxylate shunt, among other things, featuring a galactose-loving mutant.

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This was fun. Wish there were more submissions – having to write up random blog posts forces me to revisit forgotten subjects and explore new ones: I'd never brave a post on metabolic regulation on my own! By not submitting, y'all are having a deleterious effect on my education... ;-)

The next edition will be hosted by our resident microbiologist @labratting at Lab Rat, and she better get more than three submissions... come on, we do so much molecular biology in almost every field of biology! Write 'er up, dammit!