When we and other known organisms take energy from food we are actually taking molecules with higher-energy electrons, converting them into the high-energy molecules our cellular processes can use to do make cell things happen, and producing very similar molecules with lower-energy electrons. Rather than infinitely accumulating these molecules, our cells dump low-energy electrons onto another molecule that is amenable and thereby convert into a molecule ready to accept high-energy molecules from food (with a bunch of steps in between).
For us, as aerobes, the electron acceptor at the end of respiration is oxygen.
Oxygen as an electron receptor is newer than several others. Anaerobes came first. It was only after photosynthesis had produced a ton of atmospheric oxygen that it became a viable option, really. But it O2 is a comparatively good electron acceptor because the process in which it accepts those electrons allows cells to grab quite a bit of energy from that last step. It is fairly "electron needy" compared to earlier electron acceptors.
So, basically, aerobes get more energy per food unit (sugar molecule) than the vast majority of other creatures. You need it to live because it is an essential part of how your cells get food, namely, how it can recycle molecules at the last step of the respiration cycle.
talking out my ass, I'm guessing its because oxygen is an energetic and highly reactive element, and therefore it can do lots of things and it does them really well (or at least strongly), or in general was just the best most direct means to accomplish the energy intensive tasks that were required given the biosphere we evolved in? I'm not sure how common/ vital oxygen consumption was before that one mass extinction where algae became overabundant and oxygenated the atmosphere and caused a mass extinction, it could have been a result of adaptation to that new condition- though I doubt this is the case
So if this is true, why do we need it to live?
It's not true. It's sophomore high school biology students making memes about things they only have a cursory understanding of.
https://en.m.wikipedia.org/wiki/Adenosine_triphosphate
Because we evolved on the Death Planet, and life, uh, finds a way
When we and other known organisms take energy from food we are actually taking molecules with higher-energy electrons, converting them into the high-energy molecules our cellular processes can use to do make cell things happen, and producing very similar molecules with lower-energy electrons. Rather than infinitely accumulating these molecules, our cells dump low-energy electrons onto another molecule that is amenable and thereby convert into a molecule ready to accept high-energy molecules from food (with a bunch of steps in between).
For us, as aerobes, the electron acceptor at the end of respiration is oxygen.
Oxygen as an electron receptor is newer than several others. Anaerobes came first. It was only after photosynthesis had produced a ton of atmospheric oxygen that it became a viable option, really. But it O2 is a comparatively good electron acceptor because the process in which it accepts those electrons allows cells to grab quite a bit of energy from that last step. It is fairly "electron needy" compared to earlier electron acceptors.
So, basically, aerobes get more energy per food unit (sugar molecule) than the vast majority of other creatures. You need it to live because it is an essential part of how your cells get food, namely, how it can recycle molecules at the last step of the respiration cycle.
talking out my ass, I'm guessing its because oxygen is an energetic and highly reactive element, and therefore it can do lots of things and it does them really well (or at least strongly), or in general was just the best most direct means to accomplish the energy intensive tasks that were required given the biosphere we evolved in? I'm not sure how common/ vital oxygen consumption was before that one mass extinction where algae became overabundant and oxygenated the atmosphere and caused a mass extinction, it could have been a result of adaptation to that new condition- though I doubt this is the case
Organisms need some oxidizing agent to respire. We use oxygen because it's very highly reactive and thanks to photosynthesis is goddamn everywhere.
Some use radiation tho.
https://www.sciencealert.com/bacterium-lives-off-nuclear-energy-alien-life-europa
And maybe related https://en.m.wikipedia.org/wiki/Radiotrophic_fungus
Would be rad if we could live off space radiation.
Can you explain that first part in more detail? I really know nothing about this and I'm curious to hear more.