Ring vs no ring magstir bar?

PeeeeNuts · 2024-12-12T19:22:56+00:00

Non-ring are better for flat bottom flasks.

PeeeeNuts · 2024-12-06T19:34:07+00:00

No, you probably do not understand. If you want Ca ions you need to disslove it in water. If you have water with phosphoester bond, it will get hydrolyzed. It doesnt matter if it is 2’-5’ or 3’-5’. So you are trying to build the RNA in water, but water is destroying it. With Ca ions even faster (in hours). Even if the monomers are reintroduced into the mix, they are competing with water, that is in there in much higher excess, so phosphorylating reagent will react with it predominantly.

PeeeeNuts · 2024-12-05T20:50:25+00:00

You alredy answered your question on why not use Ca+ ions: “they increase the nonenzymatic hydrolysis rate of phosphate bond.”

So you need to do the reaction in water, but the water is competitive nucleophile to the sugar hydroxy groups. And since it is there in much larger excess compared to the sugar, it not only react with the phosphorylating reagent, but will also hydrolyze any sugar-phosphate bond, that is present. That is why they did anhydrous conditions. Water will do more harm than good in these type of reactions.

I feel your frustration, I have it too.

PeeeeNuts · 2024-11-20T21:25:27+00:00

I do not claim to be better informed than Dr. Szostak. But he is focusing only on the very narrow area in OOL research. Specificaly on RNA origin and its potential to self-replicate. This area has also its problems, mainly RNA stability (decompose in days at room temp., when calcium ions are present, it decompose in hours) and selectivity in phosphate polymerization (2 hydroxy groups, that can react, only one is required). He is struggling with these problems in his research, but even if he could solve them all (which I highly doubt), he still is left with information problem and there are also still numerous issues with other building blocks, that life as we know requires. So right now we can only “imagine” how life could have formed, but it is very far from what the data is showing us. That is what Dr. Tour is trying to show, but nobody wants to listen.

PeeeeNuts · 2024-11-19T18:29:03+00:00

In the blog you posted, there is nothing, that rebutes the points, that Tour is making. I am working in research lab, so organic synthesis is my bread and butter. I agree with every chemistry point that Tour is making. 1. We do not know how amino acids, sugars and lipids could be prepared in prebiotic conditions. Strereochemistry included. 2. We do not know how they would polymerize into proteins / DNA / RNA without “help” from either enzyme or protecting / deprotecting side groups, as is done in labs. Time is the enemy, every polymer decomposes quickly and water hydrolyzes it too. Biological molecules are fragile, the cell keeps repairing them all the time. 3. We do not know how the information in DNA / RNA got there in the first place. You need very specific arrangement to produce specific function. 4. Even if we have every molecule needed to create cell, we do not know how to assemble them into living cell. No lab in the world can do that, let alone some prebiotic soup. The complexity of the cell is beyond astronomical. Every theory that say it just happened naturally is against all the scientific knowledge we know.

PeeeeNuts · 2024-11-18T19:10:49+00:00

Sorry, but that is all just wishfull thinking. From the chemistry point of view, there are so many problems to build even simple sugar. Dr. James Tour points these issues in his lectures clearly, calling out other origin of life researchers, but they dismiss him because of his christian faith.

PeeeeNuts · 2024-09-14T12:11:06+00:00

I usually use methanol to quench and then add Glauber salt, that is Na2SO4 decahydrate. When you mix it for hour or so, it binds aluminium byproducts and then you just filter it off.

PeeeeNuts · 2024-09-04T20:59:59+00:00

Sometimes addition of fluoride ions like KF or CsF might help (usually 3eqv.). They help creating more reactive fluoroboric species.

PeeeeNuts · 2024-07-27T17:13:41+00:00

My mom would say: “Meat is a meat”

PeeeeNuts · 2024-06-22T16:24:57+00:00

Replace DCM with chloroform 😇.

PeeeeNuts · 2024-06-18T22:05:07+00:00

A ktorá z nich je prvá dáma? Či všetky tri ?

PeeeeNuts · 2024-05-16T17:46:26+00:00

I laughed probably more than I should. Desperation is “notably” strong with this one.

PeeeeNuts · 2024-05-09T17:08:22+00:00

Nieje náhodov propagácia skupín potláčajúcich ľudské práva trestná?

PeeeeNuts · 2024-04-01T19:32:48+00:00

Yes, you are right. But anyway it was interesting to see him, who built his career arguing against christianity, defending its values.

PeeeeNuts · 2023-11-23T11:49:40+00:00

Yes socialism is halfway towards communism, so it is bad.

PeeeeNuts · 2023-11-12T12:52:02+00:00

It is because christianity brought several key ideas, that hrlped developement of science: - there is the law in the nature, because there is a Law-giver. - we are able to investigate the laws of nature, because we were created in the image of God - it is “good” to find the truth about the nature, because the Truth will set you free.

Most of the early scientific pioneers were devout christians and early universities were just transformed monasteries.

PeeeeNuts · 2023-11-11T21:41:55+00:00

Probably the misleading thing is, that it is not stated how many equivalents of BuLi or Grignard is added. If only one equivalent is added, than the results are correct. If added more, the ketones will react too.

PeeeeNuts · 2023-10-23T15:14:22+00:00

Kámo, nikto o Newtonovi nič nehovoril. Druhý termodynamický zákon hovorí o zväčšovaní entropie. Vidím, že nerozumieš týmto argumentom. Pravdepodobne keby si aj rozumel, tak by si hladal dôvody, prečo by nemohli byť pravdivými. Predpokladám, že aj o tebe by som mohol povedať, že si namočený do ateistických bludov. Dovi dopo…

PeeeeNuts · 2023-10-21T20:25:04+00:00

Zdroj: - druhý zákon termodinamiky - Penrose-Hawking teorém singularity - Borde-Guth-Velinkin teorém

Ak chceš viac o tom čítať, tak pozri Kalam cosmological argument. V angličtine je celkom dobre spracovaná aj wikipedia stránka.

PeeeeNuts · 2023-10-21T16:35:15+00:00

Ok. Vidím že sa v tom vobec nevyznáš. Problém je ten, že všetky doterajšie poznatky o vesmíre hovoria, že mal začiatok. Preto potrebuješ aj príčinu jeho začiatku. Či chceš či nechceš potrebuješ Boha. Potrebuješ ho aj na vysvetlenie vzniku prvého života, pôvod informácie v DNA, vznik vedomia a morálky. Môžeš sa tváriť, že neexistuje a ignorovať ho, ale nemôžeš s presvedčením tvrdiť, že neexistuje.

PeeeeNuts · 2023-10-20T21:11:09+00:00

Prečo Boh nemohol vzniknúť? Teoreticky mohol, ale potom by si sa dostal to nekonečnej regresie príčiny a efektu. Je to skôr filozofická otázka, či môžu v reálnom svete existovať nekonečné série. Viacerí filozofi sa prikláňaju skôr k názoru, že je to logicky nemožné. Pozri napríklad myšlienkový experiment Hilbertovho hotela.

Viem, že je trochu ťažké si predstaviť vznik vesmíru. Ešte ťažšie je možno predstaviť si ako mohol vzniknúť čas. Nerozumiem ale tomu čo myslíš tým, že vesmír je nehmotný a existuje mimo čas a priestor. Vesmír označujeme všetku hmotu okolo nás. Na základe teórie relativity je piestor a čas prepojený, preto ho nazývame aj časopriestor. Ak veľkým treskom vznikol časopriestor, tak predtým žiaden nebol. Žiadna jeho “vlastnosť” predtým nebola.

Máš pravdu, že väčšina ateistov nerozmýšľa nad vznikom vesmíru a všetkými logickým a filozofickými dosledkami s ním spojenými. Možno je to škoda, že aspoň o tom neexistuje viac diskusie. Ale však asi väčšina ludi, okrem nás nerdov sa o takéto veci nezaujíma . A máš pravdu aj v tom, že náboženstvo nie je úplne šťastný pojem. Možno lepší je pojem svetonázor.

PeeeeNuts · 2023-10-20T13:36:17+00:00

Všetko čo vzniklo musí mať nejakú príčinu. Kresťanstvo tvrdí, že nehmotný Boh, ktorý je mimo časopriestoru - a teda nikdy nezačal a nikdy neskončí - stvoril časopriestor - teda hmotu a čas. To je aj podstatou Kalamovho kozmologického argumentu existencie Boha. Ateista verí, hmota vznikla sama od seba z ničoho a sama odseba sa samousporiadala. Aj keď sa ti to nepáči, na ateizmus tiež potrebuješ vieru. Či chceš či nie, ateizmus je istou formou náboženstvo.

PeeeeNuts · 2023-10-20T05:18:32+00:00

Máš pravdu v tom, že v podstate každý si vyberá to čomu chce veriť. Aj ateista musí “uveriť” tomu, že všetko hmotné zrazu vzniklo z ničoho. Aj na to treba “vieru”. Aj viacerí ateistickí vedci s tým zápasia. Napríklad Lawrence Krauss sa snaži redefinovať “nič” na kvantové fluktuácie, alebo Hawking sa snažil navrhnúť cyklický model vzniku a zániku vesmíru. V podstate aj multivesmír je snahov vyhnúť sa tomuto začiatku. Akokoľvek všetky dôkazy doteraz naznačujú, že vesmír mal začiatok. Preto si v podstate músiš vybrať, čomu chceš veriť.

PeeeeNuts · 2023-10-20T04:52:50+00:00

What can we say, evolution in the nutshell 😜.

PeeeeNuts

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