Small Things Considered

Pictures Considered #57: Coloring a Cell

by Christoph
Our ability to visual­ly per­ceive and dis­cri­mi­nate is al­ways sligh­ly over­whelmed by black-and-white ima­ges. Es­pe­cial­ly, of course, when the ob­jects de­pict­ed are out­side our trained, fa­mil­iar size spec­trum, such as bac­te­ri­al cells and their in­nards. Take for ex­ample Fi­gure 1, the cryo-ET image of a ti­ny... Read more →

Pictures Considered #56: A Pinch of Salt

by Christoph | Micro­bio­lo­gists deal with salt, sodi­um chlo­ride, all the time. Most growth me­dia for our cher­ished re­search con­tain at least "a pinch of salt." Or we need salt as a com­po­nent of buf­fers for bio­che­mi­cal ex­pe­ri­ments that re­quire de­fined con­cen­tra­tions of Na⁺ and Cl⁻ ions. How­ever, we usu­al­ly on­ly see crys­talline salt when we take... Read more →

Pictures Considered #55: Conjugation, and some pairing issues

by Christoph | If you've ever taken a class on bac­te­ri­al ge­ne­tics, ei­ther re­cent­ly or in the last few de­ca­des, you've no doubt seen this image: the con­ju­ga­tion of two bac­te­ri­al cells (Figure 1). And if you found this image so self-ex­pla­na­to­ry that you didn't both­er to ask for the source, you're not alone. The in­ter­net is re­plete with it, in vary­ing... Read more →

Pictures Considered #54 : Mitochondria can't swim...

by Christoph | ...and get pushed around in­stead. Not equip­ped with fla­gel­la for pro­pel­ling or Type IV pi­li for twit­ching they can't ac­tive­ly move. But one step at a time. If you re­call what you know about mi­to­chon­dria, you may pic­ture them as ovoid or bean-shaped or­gan­el­les, house­mates float­ing in the eu­kar­yo­tic cyto­plasm. They are... Read more →

Pictures Considered #53 : The ocean water column is profoundly dark...

by Christoph | ...for the most part. And it's vastly deep­er than the dia­gram Ro­ber­to showed in his re­cent post "The Bio­lo­gi­cal Pump." The eu­photic and meso­pe­lagic zone sizes are cor­rect, but do not even ap­pro­xi­ma­te­ly co­re­late with their ver­ti­cal re­pre­sen­ta­tion in the dia­gram. Why is this a point... Read more →

Pictures Considered #52 : Streptomyces stacks Z-rings...

by Christoph | Streptomyces stacks Z-rings... into lad­ders in­side its aeri­al/spo­ro­gen­ic hy­phae. If this sen­tence strikes you as a bar­rage of jar­gon or just gib­ber­ish, don't des­pair, help is coming. First, en­joy the "light show" in the 20‑se­cond video clip on the right side. It runs in loop, so you can fol­low more than... Read more →

Pictures Considered #51 : Headful Packaging, Literally...

by Christoph | For more than two decades we have known that the doub­le-stran­ded DNA of pha­ges is neat­ly rol­­led up in their cap­sids and fills them com­ple­te­ly. Cerritelli et al. (1997) have de­mon­stra­ted this for coliphage T7, and later Jiang et al. (2006) for Sal­mo­nel­la phage ε15. Yet, with a length of ~40 kb, both phages have more 'me­di­um si­zed' ge­nomes, and it is fine to learn now... Read more →

Pictures Considered #50 : The Four Kingdoms of Nature

by Christoph | We often talk sloppily of «algae» or «pro­tists» on these pa­ges when we con­si­der, ra­re­ly enough, uni­cel­lu­lar eu­kar­yo­tes. For my part, I at­tach little im­port­ance to bio­lo­gi­cal sys­te­ma­tics or taxo­no­my per se be­cause I'm more in­ter­es­ted in learn­ing how li­ving be­ings go about their bu­si­ness than in sort­ing them in­to va­ri­ous draw­ers. The­re­fore I most­ly con­fine my­self to the names of the... Read more →

Pictures Considered #49 : C-Reactive Protein

by Elio | Among the blood tests that your doctor may prescribes is the one for C-Reactive Protein (CRP). What is it? CRP is a protein made by the liver in response to inflammation anywhere in the body, so a positive result will alert the physician that something along those lines is going on some place within you. Read more →

Pictures Considered #48 : Contributions to the Biology of the Bacilli

by Roberto | It was fifteen or twenty years ago, I can't recall the year any more. But I vividly remember walking into Harvard's Farlow Botany Library, being shown to a seat next to an elegant wooden table, and asked to don a pair of white gloves. The protocol stemmed from the fact that I had requested to see an original of the second volume of the journal Beiträge zur Biologie der Pflanzen (Contributions to the Biology of Plants), from 1876. Read more →