Mastodawn

New post! On the #chemistry of #purple, my favourite colour 💜

https://keiran-rowell.github.io/dyes/2025-11-05-aniline-and-the-german-chemical-industry/

This tale winds its way past sea snails and togas 🏛️, coal tar and dream snakes 🐍, industrial conglomerates and chemical theory ⌬ ⟷ ⏣, to flow back in recirculation to fundamental light-sensitive cells themselves 👁️💡🦠

Spend time with this hue right at the edge of our perception 🎨

#benzene #Kekulé #dyes #BASF #organic #porphyrin #GravitysRainbow #Pynchon #Perkin #rhodopsin #HistoryofScience #orbitals #art

From Muck to Mauve: the creation of modern dyes from coal tar

Content notice: this post discusses the early dye companies of industrialised pre-WWI Germany that were at one point put to horrific wartime use. World War II is alluded to in a literary work that was famously denied a Pulitzer prize in part because of its confronting content.

Keiran Rowell

Keiran Rowell Jun 3, 2024

https://youtube.com/watch?v=NjrFe7JHY1o&si=AnMb1ScqOXwNj5ag

*Beautiful* animation and explanation of how our eyes turn light into electrical brain signals. 👁️🧠

A single photon causes a twist in one rhodopsin molecule, setting up a signal cascade that closes pores between membrane stacks filled with charged atoms.

Kind of like the cells in a battery 🔋 this causes a 1 millivolt drop, enough to send off electrical signals to your neurons conveying that you detected a photon! 〰️

#vision #phototransduction #rhodopsin #animation

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PLOS Biology Jan 9, 2024

Retinal #photoreceptor cells are maintained through a complex #ProteinTrafficking network. @RobichauxLab use quant super-res microscopy to reveal trafficking of the visual pigment #rhodopsin in the inner segment region of rod photoreceptors #PLOSBiology https://plos.io/3RPJPVW

Super-resolution mapping in rod photoreceptors identifies rhodopsin trafficking through the inner segment plasma membrane as an essential subcellular pathway

Photoreceptor cells of the retina are maintained through a complex protein trafficking network. This study uses quantitative super-resolution microscopy to reveal the trafficking of the essential visual pigment rhodopsin in the inner segment region of rod photoreceptors.

Lukas VFN 🇪🇺Oct 29, 2023

Some #microalgae smartly switch energy systems to support growth under nutrient limitation https://microbiologycommunity.nature.com/posts/some-microalgae-smartly-switch-energy-systems-to-support-growth-under-nutrient-limitation

#Plastid-localized #xanthorhodopsin increases #diatom biomass and ecosystem productivity in iron-limited surface oceans https://www.nature.com/articles/s41564-023-01498-5

"marine #diatoms, a globally important group of #algae can switch between #photosynthesis and a light-driven #rhodopsin proton pump to support growth in iron-deprived waters"

#protists #microbes #metabolism #plankton

Some microalgae smartly switch energy systems to support growth under nutrient limitation

In a recent article published in Nature Microbiology, we show how marine diatoms, a globally important group of microalgae can switch between photosynthesis and a light-driven rhodopsin proton pump to support growth in iron-deprived waters. (Poster image: Oliver Skibbe, CC BY 4.0)

Springer Nature

astropage.eu Apr 3, 2023

Neue Erkenntnisse über den #Sehsinn der #Walhaie

https://www.astropage.eu/2023/04/03/neue-erkenntnisse-ueber-den-sehsinn-der-walhaie/

#Walhai, #Rhodopsin, #Wellenlänge, #Tiefsee

Neue Erkenntnisse über den Sehsinn der Walhaie | astropage.eu

Eine Forschungsgruppe mit Beteiligung von Professor Mitsumasa Koyanagi und Professor Akihisa Terakita der Osaka Metropolitan University Graduate School of Science hat die genetischen Informationen und die Struktur des Fotorezeptors Rhodopsin untersucht, der für Wahrnehmung schwachen Lichts bei Walhaien verantwortlich ist. Die Studie zielte darauf ab festzustellen, wie Walhaie bei dem schwachen Licht in extremen Tiefen

astropage.eu

Scientific Frontline Mar 29, 2023

Investigating both the #genetic information and structure of the #photoreceptor #rhodopsin, responsible for detecting dim light, of #whale #sharks to investigate how they can see in the dim light at extreme depths.
#MarineBiology #sflorg
https://www.sflorg.com/2023/03/mb03292301.html

How whale shark rhodopsin evolved to see, in the deep blue sea!

the photoreceptor rhodopsin of whale sharks

CellBioNews Dec 30, 2022

Belt and suspenders: #Alpine #lake #bacteria deploy two light-harvesting systems.

#rhodopsin #bacteriochlorophyll

https://phys.org/news/2022-12-belt-alpine-lake-bacteria-deploy.html

Belt and suspenders: Alpine lake bacteria deploy two light-harvesting systems

Though humans, along with other vertebrate and invertebrate organisms, don't photosynthesize, we're definitely the downstream beneficiaries of the life forms that do. Phototrophic organisms at the bottom of the food chain convert abundant sunlight into the energy that ultimately powers all other life.

Phys.org