by Roberto — It's been almost a year since our last puzzle, here's another one. Quite appropriate to have a test at the end of the semester. If you've kept up your STC reading, this may prove an easy test. If you haven't... Well, this is your chance to catch up. Read more →
Lubert Stryer (1938–2024)
by Roberto — Second semester, senior year at Carnegie-Mellon. Newly minted Assistant Professor Bill Brown, with whom I was learning to do peptide mapping, runs into the lab with a huge smile holding a deep blue book with a mesmerizing structure on its cover: "Look at what Stryer has done, this is so beautiful!!" Read more →
Oscillibacter and Cholesterol
by Roberto — From its humble beginnings as an inhabitant of the Japanese corbicula clam alimentary canal to center stage attention-getter as a cholesterol-lowering resident of the human gut, Oscillibacter has experienced a meteoric rise to stardom... Read more →
Of Terms in Biology: Kymogram
by Christoph — In his presentation at a meeting in Copenhagen last year, Johan Elf showed several kymograms. No, these are not fancy versions of pie charts that everyone knows, but an intuitively accessible visualization of the localization of macromolecular complexes in living bacterial cells as they change over time. Read more →
Of Terms in Biology: Ecological Drift
by Roberto — In last Monday's post I presented Mike Vellend's "Theory of Community Ecology," which posits that selection, drift, speciation, and dispersal are the processes that interact to determine community dynamics. Today I'm going to expand on the process of "ecological drift." What is that? Read more →
Microbial Community Ecology
by Roberto — Many present-day microbial ecology studies involve some sort of sequencing effort to determine which microbes are present in a sample. It seems that during the last three decades, every conceivable ecosystem of Earth and its inhabitants has been thus explored. But, what have we learned? Read more →
On the Origin of (the Word) Species
by Roberto — Systematic classification of organisms is a fundamental part of biology. Yet, despite its being essential, the species concept has a problem; there is still no universally accepted definition. Read more →
Hey flagellum, shift into reverse gear!
by Christoph — In a classical manual gearbox, a gearwheel is inserted between the countershaft and the drive shaft. This reverses the direction of rotation of the drive shaft. Flagella have found a smart solution to do without an additional gearwheel in their gearbox: They run their engine along the outside of a gearwheel or, if they reverse the direction of rotation, on its inside. Read more →
Never a Dull Enzyme
by Roberto — The tricarboxylic acid cycle enzyme citrate synthase from Synechococcus elongatus has the remarkable feature that it self-assembles into multimeric fractal shapes, specifically Sierpiński triangles. As Arthur Kornberg would have said: "Never a dull enzyme!"... Read more →
Of Terms in Biology: Phage–Plasmid (2|2)
by Christoph — In the first part of this piece on phage–plasmids (P–Ps), I focused on examples that are well known today, and on the fact that they are representatives of larger families with dozens of members, rather than peculiar solitary cases. Here now, in the second part, I will introduce some lesser-known examples of phage–plasmids. Read more →