April 09, 2016 at 02:21AM

Tody I Learned: 1) Something really cool about working with TX-TL that I can't actually talk about (IP stuff). Sorry, but it really is TIL-worthy, I swear! 2) A little tiny bit about how diatoms* and radiolarians** make their shells. It all comes down to vesicles, perhaps unsurprisingly -- many microorganisms appear to be capable of causing silica-based mineralization on the surfaces of specialized vesicles. The cell will pull a vesicle into roughly the right shape, often an oblong "plate" or tubular "pole", using microfilaments and microtubules as a kind of guy wire, or by stretching them across the surface of some other, larger vesicle. Once in place, the vesicle is triggered to mineralize, making a hard plate, scale, or other structural component that can be guided to the outside of the shell. The above process seems to be the primary means of construction of diatom shells. Radiolarians (and I think, to some degree, diatoms as well) use a different variation on this technique to make net-like, porous coverings. This is accomplished by making a vesicle "foam" around the nucleus or cell exterior. Mineralization is tuned to only occur where two vesicles touch. So what you see in a radiolarian shell is actually a network of intersections in a foam of vesicles. More information in section 7.3 of "Biomineralization: Principles and Concepts in Bioinorganic Materials Chemistry" (http://ift.tt/25QzpaF). Thanks to Mengsha Gong for teaching me about this! * http://ift.tt/20oD8rL ** http://ift.tt/25QzpaH 3) ...about a rather contentious molecule among vegans -- cysteine. Yeah, the amino acid. Turns out most cysteine is derived from hydrolized animal hair and feathers, which makes it a no-go for vegans. This also explains some of my confusion about Einstein Bagel Bros bagels, as sources differ drastically about which of their bagels are vegan. It seems that all or almost all of their bagels contain industrial cysteine, which has led them to label their bagels as non-vegan... but less strict vegans may be ok eating pretty much all of their bagels.