Edit: I’ve had a lot of fun reading all of your analogies
In: 64
Adaptation is mostly a result of mutation. Since bacteria reproduce so fast the can mutate and adapt quickly. As for why heat and radiation are harder to adapt too. It’s mostly because of the amount on energy. Heat and radiation are far more energy than chemicals.
This is very summarized. The truth of it is multiple independent fields of research.
My best explanation is that with antibiotics, one bacterial population is being consistently challenged by the same antimicrobial for 1-2 weeks on average. With disinfectants, you are theoretically always cleaning a different bacterial population. Think in a hospital, you’re cleaning up after each patient one time then it’s onto the next patient.
The repeated, constant exposure of a given bacterial population to a given antimicrobial is what breeds resistance over time because this population has the time to withstand multiple generations during the course of treatment. This is why it’s so important to finish a course of antibiotics.
Antibiotics are organic chemistry — i.e. the same stuff life is made of. A bacterium interacting with an antibiotic is like two chess pieces interacting.
Heat, strong acids etc aren’t organic chemistry, they’re physics/physical chemistry. It’s more like a chess piece vs a car.
Killing bacteria is easy. Killing bacteria without killing the patient takes a much more subtle approach. That more subtle approach means that the bacteria have a chance to adapt.
Also: Soap does not kill bacteria! Soap only helps /remove/ bacteria!
EDIT: It’s like the difference between trying to kill someone with a slow acting poison vs dropping them into a volcano. The slow acting poison means some individuals might actually survive.
Antibiotics can do a few things. They can either inhibit cellular protein synthesis (example, inhibiting DNA transcribing), which can affect bacterial cell walls and metabolism and lead to cell death. These target specific points in pathways, so if bacteria in a colony has a different pathway to make proteins or their cell walls are composed of a different composition then the antibiotic won’t work.
Picture this, a colony of bacteria has a pathway to make an important protein. It goes from A, to B, to C. The antibiotic messes up A to B so C can’t be made. But a few bacteria go from A to D to C, so that method won’t work.
Extreme changes to heat and pH denatures (permanently changes) the structure of the proteins that make up cells. They cannot adapt to it because at a fundamental molecular level the bonds between amino acids are affected too much.
You can change the locks on your house, and it’ll keep your ex out, but it won’t stop a freight train from plowing through the front door.
Bacteria need to let things in to do chemistry, and control what those things do inside of the cell. Things that specifically target bacteria must somehow exploit this process to get inside and do damage – this is why they don’t also kill humans or plants. They ‘have the right key’.
Heat, powerful acids, powerful oxidizers, and other ‘blunt’ attacks will just as soon kill you as they will bacteria, because they don’t exploit anything. They just smash through whatever’s in their way. These are the ‘freight train’ attacks.
Soaps bind to and remove fats. Bacteria are basically inside a container made of fats. It’s not really feasible to change their entire outer layer via natural random little variations.
It’s like asking why you can adapt to gripping a heavy barbell but not to a piano falling on your head. It’s too big a stimulus and the damage is too extreme, so it kills you every time and you can’t adapt your way anywhere near surviving it.
Heat/acid/soap are fundamentally destructive for ALL cells/organic matter (humans have relatively thick skin that protects us from these effects), as it literally rips the cell apart – there’s no realistic way a bacterial cell could protect itself from this. Antibiotics are much more targeted and don’t physically destroy the cell, rather they enter the cell and prevent the bacterium from building it cell wall / membrane, causing it slowly break down. Certain bacteria have evolved ways of preventing the antibiotic from entering, resulting in antibiotic resistance.
There are bacteria which live in superheated water which would kill most bacteria. They’re called hyperthermophiles and they live near volcanic vents.
They probably evolved in a manner similar to how antibiotic resistant bacteria develop. With antibiotics, some bacteria are exposed only slightly, manage to survive, and develop resistance. With heat, exposure to lesser heat levels doesn’t kill all the bacteria – some develop a little more resistance and reproduce, and later and later generations are able to handle higher and higher temps.
It doesn’t take as long with antibiotics as it does with environmental factors because of reasons others have given, but it can happen over time.
Antibiotics disrupt specific processes in bacteria to kill them. Antibiotics are used in living creatures, like a human, so they can´t disrupt the creature’s cells. It has to be a way for a living cell to handle the antibiotics. The result is has to exploit the differences in a careful way.
Acid and soap destroy the membranes that cells are made of. It would kill human cells too. The top layer of our skin is dead cells, there is a reason soap burns if you get it in your eyes or mouth, it kills cells that are exposed to it.
There is the acid in your stomach, but the reason it does not kill the cells is it is not in direct contact, There is a mucus-bicarbonate barrier that separates them and neutralizes the acid.
It does not have to kill cells, it has to kill just some cells but not others like bacteria in a human but not the human cells
The difference is a bit like a thief that tries to pick your lock is the antibiotics, the bacteria has a lock that has the tool to open but the host cells have a different type of lock the thief does not have tools for. To stop the thief you just need to change the lock a bit so their tools do not fit the lock
The acid/soap will be a military force that tries to enter a building in a war zone. They put plastic explosives on the wall to breach the. Tanks, artillery, and bombs can be used too. They will do a lot of damage on that bounding and on others too, and there is no real way to stop them. A bunker is better protected so it is harder to get in but it is still possible to do so.
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