31–40 of 104 posts
It would be interesting to see a heat map for reading an article like this. It’s so long.. after 10 minutes I wanted to know the point of it, so I skipped aggressively to the middle, found a few points, then skipped to the end. I wonder if there’s any value to so many words in this day and age with so many other things to read on the internet.
It would be interesting to see a heat map for reading an article like this. It’s so long.. after 10 minutes I wanted to know the point of it, so I skipped aggressively to the middle, found a few points, then skipped to the end. I wonder if there’s any value to so many words in this day and age with so many other things to read on the internet.
Really like this analogy: It is a somewhat astonishing fact of life that the exact same DNA is shared by every cell in your body, from the skin to the brain; those cells differ in appearance and function because, in each of them, a molecular gizmo “transcribes” some DNA segments rather than others into molecules of single-stranded RNA. These bits of RNA are in turn used as the blueprints for proteins, the molecular m…
'Molecular machines' is not an overstatement. Here's an example of some of them working in harmony to maintain an essential electrochemical gradient across the lipid bilayer that encapsulates the mitochondria: https://www.youtube.com/watch?v=LQmTKxI4Wn4 It's a 7 minute video, if you only have a little time, skip around, but make sure you listen to the part starting at 6:17. DNA isn't just the blueprint for the machin…
Never seen the chemical (proton concentration), converted into something mechanical (spinning), and back into chemical (adp + phosphate -> atp) in such a way before.
Many paragraphs into the article and I still don’t know what important discovery or observation has been made
This kind of reporting interleaved with storytelling in a really weird voice is frustrating. Why do journalists write like this? What purpose does this word salad serve? I can do this myself! "On a bald September day, a man walks into a barber shop, languishes at the occupied seats, and voilà, while sensing upcoming bowel movements, he discovers the next great theory of economics."
> For the first half of the twentieth century, the going theory was that the invading element—the “antigen”—served as a template around which a corresponding antibody was molded. Only in 1955 did scientists discover the much stranger truth. It turned out that the cells that produce antibodies—called B cells, because they were first discovered in the bursa of Fabricius, an organ that does for birds what bone marrow does for humans—can produce only one kind each. Its structure is random, and nearly every B cell is discarded unused. If, however, an antibody created by a B cell happens to match some part of an antigen, that B cell will not just survive but clone itself. The clone incorporates many mutations, which offer the possibility of an even better match. After a few generations, an antibody with the best fit is “constructed” through a process of mini-evolution that occurs continuously in our lymph nodes and spleen. (Our ancestors the bony fish adapted the machinery of the B-cell system from an even more ancient parasite.)
So, natural selection discovered a way to run an embedded natural selection search process in an individual. Talk about meta.
This is mind blowing: > For the first half of the twentieth century, the going theory was that the invading element—the “antigen”—served as a template around which a corresponding antibody was molded. Only in 1955 did scientists discover the much stranger truth. It turned out that the cells that produce antibodies—called B cells, because they were first discovered in the bursa of Fabricius, an organ that does for bir…
[1]: https://en.wikipedia.org/wiki/V(D)J_recombination "V(D)J recombination"
Many paragraphs into the article and I still don’t know what important discovery or observation has been made
If you're looking for the summary, it's about 1/4 the way in. > Usually, the viruses that humans care about are successful because they shut down both of these signalling programs. The coronavirus is different. “It seems to block only one of those two arms,” tenOever told me. It inhibits the interferon response but does nothing about the cytokines; it evades the local defenses but allows the cells it infects to call…
In a nutshell, SARS-CoV-2 (COVID-19) does block interferon response by using molecular mimics. Some of the proteins encoded in the virus are really similar to proteins in the interferon pathway, so this is not surprising. Still pretty unexplored and a nice route towards finding treatments.
Now, the interesting part is that the dynamics of interferon is very non-linear. Cells exchange interferon signals with other cells in the same tissue to pass information and coordinate with the immune system. There are fairly sophisticated models (using stochastic message passing!) that confirm lab observations on regular non-infected cells [1].
My hypothesis is that by blocking interferon in a sufficient number of cells on individuals with already disrupted innate immunity (due to ageing, insulin resistance, etc.) the system becomes chaotic. Infection by e.g. pneumococci is tolerated because the signaling is perturbed and then, all of a sudden, you get a massive amount of proinflammatory molecules secreted and cells decide to undergo apoptosis. That's the cytokine storm that everyone talks about.
Sadly, pursuing these ideas within academia is hard as most (but not all) biology labs are really hostile to mathematical models, even if they explain or predict things they can't using hand waving. Perhaps I should seek VC funding.
This is mind blowing: > For the first half of the twentieth century, the going theory was that the invading element—the “antigen”—served as a template around which a corresponding antibody was molded. Only in 1955 did scientists discover the much stranger truth. It turned out that the cells that produce antibodies—called B cells, because they were first discovered in the bursa of Fabricius, an organ that does for bir…
It’s mind blowing not only how our body mimics natural selection with B cells, but also how it generates the genetically diverse B cells in the first place. [1] [1]: https://en.wikipedia.org/wiki/V(D)J_recombination "V(D)J recombination"
So, in a way, different individuals have different immune strategies. For example, super-responders to HIV tend to be HLA-B57. This HLA "version" trades better response to virus that mutate quickly for more chances of autoimmunity as thymic selection is less stringent (because HLA-B57 presents less selfpeptides in the thymus).
It would be interesting to see a heat map for reading an article like this. It’s so long.. after 10 minutes I wanted to know the point of it, so I skipped aggressively to the middle, found a few points, then skipped to the end. I wonder if there’s any value to so many words in this day and age with so many other things to read on the internet.
Agree 100%. I utterly despise modern “long-form” structure which mandates that the first 1/3 of the article have nothing to do with the headline.
Earlier quoted context omitted.
'Molecular machines' is not an overstatement. Here's an example of some of them working in harmony to maintain an essential electrochemical gradient across the lipid bilayer that encapsulates the mitochondria: https://www.youtube.com/watch?v=LQmTKxI4Wn4 It's a 7 minute video, if you only have a little time, skip around, but make sure you listen to the part starting at 6:17. DNA isn't just the blueprint for the machin…
Thanks for posting this. Looked further into atp synthase. Absolutely amazing. A little turbine, driven by the flow of protons, spinning in 120 degree discrete clicks, around catalyst pockets, where each click changes the shape of the pocket to a new one. And after the pocket has gone through a complete cycle, adp and phosphate have been fused. Never seen the chemical (proton concentration), converted into something…
This channel has a ton of great videos:
https://www.youtube.com/user/WEHImovies/videos
Here's one on kinetichore and mitosis (which also shows kinesin and dynein which are comically odd) - https://www.youtube.com/watch?v=IvJrDsRuWxQ
There's a collection of their DNA ones here: https://www.youtube.com/watch?v=7Hk9jct2ozY
Here's another view of the ATP synthesis process that shows the chaos a bit more: https://www.youtube.com/watch?v=OT5AXGS1aL8
When I think of these systematically I just wonder what the intermediate steps were. The proton pump uses energy to create the potential gradient that ATP synthase runs on. You can't have a proton gradient without the proton pump, and without the proton gradient you don't have ATP. So these two exquisitely complex machines depend on each other and had to evolve together. It boggles my mind.
Edit: Ah! Was looking for this one, sodium potassium pump - https://www.youtube.com/watch?v=ZKE8qK9UCrU This is how our neurons propagate signals. They are driven by ATP.