/sci/ - Science & Math

[Anonymous No.10521582]

how do viruses and prions function?
I mean they aren't alive and all, it's crazy that we are trying to go to space but don't even understand shit on our fingers

[Anonymous No.10521588]

>>10521582
They are literally machine code running in loop.
Its not fucking magic.

[Anonymous No.10521607]

>>10521582
>prions
The real villains. They cause nothing but destruction.

[Anonymous No.10521627]

>>10521588
>They are literally machine code running in loop.
we all are

[Anonymous No.10521633]

>>10521627
but muh free will

[Anonymous No.10521640]

>>10521627
This. I think I first learned about them reading the jurassic park sequel as a kid and it spooped me.

[Anonymous No.10521645]

We understand pretty well viruses.

[Anonymous No.10521646]

>>10521627
Woah....

[Anonymous No.10521647]

[Anonymous No.10521715]

>>10521647
How do we solve the prion problem?

[Anonymous No.10521731]

>>10521627
>>10521588
>>10521582
Life is a social construct

[Anonymous No.10521760]

>>10521731
social constructs are a social construct

[Anonymous No.10521779]

q- are prions a living entity like bacteria, or a zombie like virus or a glitch in the dna system. i m noob to this and wiki doesnt help

[Anonymous No.10521784]

>>10521779
also if humans are said to be top of the chain why tf are these hunting us

[Anonymous No.10521790]

>>10521582
They are alive.

[Anonymous No.10521882]

>>10521715
Give hella money to scientist.

[Anonymous No.10521908]

>>10521779
They are a misfolded protein in neurons that causes other proteins to misfold.
They cause spongiform diseases like Kuru, Scrapie, etc.

[Anonymous No.10521930]

>>10521908
so its like a disease to the protein right? im assuming protein is an ingredient to dna

[Anonymous No.10521951]

>>10521930
>protein is an ingredient to DNA
No
>like a disease
Sort of - there is nothing really like a prion to compare to.
The largest transmission path for Kuru (just for example) is eating the brain tissue of someone with it, hence it is only an issue in some specific populations.

They are an interesting topic but should not be confused with viruses or viroids since they have absolutely no genetic material.

[Anonymous No.10521973]

>>10521588
It kind of is magic

[Anonymous No.10522517]

>>10521582
we understand both. viruses have protein complexes that recognize antigens on cell surfaces to activate infection machinery.

prions:
all amino acid sequences have a number of possible spatial configurations because chemical bonds can rotate. Each configuration is associated with a stability. if you imagine having two strong magnets on a length of string, the magnets will prefer to either be together or as far apart as possible. That's how proteins work too, except there's at least 30 magnets, and there are at least 4 different "poles" (+ and - charged AAs interact, hydrophobic with hydrophobic, hydrophilic with hydrophilic, charged, and polar solvent, cysteines with other cysteines, and so on). on a chemical level, everything is always shaking and vibrating (temperature is the magnitude of this property), so your 30 magnet length of string will keep rearranging until its in its most stable form, or oscillating between a few similarly stable forms.
A prion is just a protein which functions when in its correct configuration, but has a more thermodynamically stable configuration which is not kinetically favored (this means, it would rather be thermostable, but it will take a long time to reach this configuration). ALSO this more thermostable configuration allows it to associate with copies of itself, forming filaments.
Your cells are already filled with protein filaments (cytoskeleton), so proteins which self associate to form filaments are not that crazy. prions form filaments so effectively that they lengthen until the cell bursts, carving holes in your brain.
sickle cell anemia works in a similar way, the reason they're sickle shaped is because hemoglobin is mutated to a version that can self-associate to form filaments, bending the cell into that shape and often causing the cells to burst.

[Anonymous No.10522521]

>>10522517
cont'd
The only thing i haven't heard an explanation for is how prions convert pre-prions into themselves, but an enzyme catalyzing a chemical change isn't that unthinkable, it's literally their definition

[Anonymous No.10522546]

>>10521647
>prion
>tons of alpha helixes
what a joke. Prions are primarily beta sheet structures.

[Anonymous No.10522548]

>>10522517
posting an energy diagram in a prion discussion, anon i like you. graduate level?
This guys explanation is spot on by the way. Prions are just thermodynamically stuck in a useless conformation, and can influence other native proteins to take such conformation, usually by stabilizing it.

[Anonymous No.10522570]

>>10522521
It's an active area of research but as I understand it, this occurs in proteins which already interact with other copies of the same protein. In the prion, the interaction domain is stable in a different conformation from the healthy domain. When a healthy protein's interaction domain meets the prion domain, it's forced into a different but kinetically stable conformation.

As a shitty analogy, if you only shake hands with your right hand and someone comes up to you with their left hand out, you have to twist your arm around to meet up. Now imagine that your arm is now stuck like that, and it can cause the position of the rest of your body to change.

[Anonymous No.10522590]

>>10522517
To take a perhaps less technical approach. Prions and prion replication can be thought of as a process that releases potential energy stored by normal processes that produce biologically useful pre-prions.

Our bodies fold proteins into a useful shape. But by some fluke of chance, pre-prion proteins are precariously positioned such that with the right nudge, they can fold down to a less precarious - more stable - configuration.

By an even worse fluke of chance, this less precarious configuration is exactly the shape needed to shove more of these unlucky proteins down the slope into the stable configuration.

There's no mysterious force, literally just unlucky proteins being pushed into a stable shape which is exactly the sufficient condition for the unlucky proteins being pushed in the first place. Think of it like a popsicle stick reaction.

https://youtu.be/e7DEJ4V4hLc?t=15.. It's just a cascade of energy being released. Actually very thermodynamically satisfying if you can get past the part where it's deadly.

[Anonymous No.10522656]

>>10521627

[Anonymous No.10523180]

>>10522548
Not him but my graduate level tertiary protein structure lecture was fun as fuck. Got to flex on the alphabet soup-memorizing immunology and cancer bio brainlets

[Anonymous No.10524798]

>>10522548
No but i will be next year. I'm glad you agree with my explanation. I know it made theoretical sense but I've never read literature on prions.

>>10523180
Thanks for posting that picture, I considered it but figured a 2d example is more accessible.

>>10522590
I like your explanation, although it's verbose at times (as was mine). I tried to make it accessible with the magnet example. I keep trying to figure out how i'll explain proteins to my blue collar extended family when i see them this summer and they ask about my studies.

[Anonymous No.10524808]

>>10522590
Do you know of any literature explaining the catalytic mechanism of prions?

[Anonymous No.10524821]

>>10521731
fin the way to deactivate the system they're exploiting through gene therapy or fin a way to destroy said protein without killing its host.
Both are extremely difficult if not impossible.

[Anonymous No.10524907]

>>10521582
"alive" is an arbitrary label. All "living" things are just replicating chemistry, just like viruses and prions. We're not living in the 18th or 19th century, no one buys the whole "elan vital" vitalism anymore. It's sad that /sci has come to this... brainlets posting really obviously tardoid speak.

Learn to biology. "Alive" is meaningless.

[Anonymous No.10524923]

>>10524907
"Biology" is a sub-category of "chemistry", which is a sub-category of "physics".

[Anonymous No.10525147]

>>10524798
Fair, for sure. Wasn't necessarily going for less verbose, but less technical in strictly in terms of terminology. But who knows maybe it wasn't needed lol

>>10524907
This is absolutely some dumb scientism shit. Life is not an arbitrary label, Viruses and prions are not alive. Prions and viruses are absolutely functionally distinct from 'alive' things.

With prions, replication occurs, but only replication occurs. Things philosophers/some scientists call alive are things which (1) replicate and (2) embody encoded instructions to procure and realize the conditions under which further replication is possible (i.e. seeking out food, shelter, love..etc)

Prions require such conditions to preexist, namely pre-prion proteins. Alive things *make* such conditions exist.

Read:
https://www.amazon.com/Incomplete-Nature-Mind-Emerged-Matter-ebook/dp/B005LW5JAS

[Anonymous No.10525227]

>>10524798
Tbh I'm not the biggest fan of that 3D representation, I found it a bit confusing at first