BEING SCIENTIST

Congratulations! By the time you reached here you would have taken 6 breaths on average so why is oxygen such an essential contributor to life on earth , why is it the fundamental of the four basic needs that sustains life on earth the others being water food and sunlight . if we humans as a species were to inhabit another planet with an atmosphere that could contain oxygen or not our fate would depend on oxygen but what if it didn’t have to .Is it possible to survive without oxygen as right now that is the only limiting factor for multiplanetary speciation
To get the energy to read this blog you need food , the whole idea of needing oxygen is essentially behind this now lets dwell deep into the biological aspects
food we eat gets broken down into proteins carbohydrates and lipids and fats in a process that we call cellular respiration which is an catabolic process , this tiny particles of food enter our cells protein become amino acids carbohydrates become glucose and fats become fatty acids and glycerol , these particles are now in the cytoplasm of the cell where they enter into a complex process called the glycolytic pathway this process converts glucose into pyruvate which is a 3 carbon molecule this is an 10 step process with intermediates like Glucose-6-phosphate
Fructose-6-phosphate
Fructose-1,6-bisphosphate
Dihydroxyacetone phosphate
Glyceraldehyde-3-phosphate
1,3-Bisphosphoglycerate
3-Phosphoglycerate
2-Phosphoglycerate
Phosphoenolpyruvate
and each step is catalyzed by enzymes present in our cells firstly we add phosphate bonds to the molecules utilising energy (ATP) after which in the later steps breaking of the phosphoanhydride bonds releases an enormous amount of energy in the form of ATP which you are currently using to read this blog after which the food particle(now pyruvate) enters another pathway called the link reaction here this pyruvate has to undergo decarboxylation it is this place where we begin to synthesis the carbon dioxide that we let out during respiration . here another energy rich molecule the NADH is also synthesized . next this pyruvate now enters our mitochondria where it begins another process termed the Krebs cycle . The mitochondria is the powerhouse of the cell and it is here that we actually use the oxygen we breather but before that through the Krebs cycle which takes place in the mitochondrial matrix the food particles (now Acetyl Coa) combines with Oxaloacetic acid undergoing a cyclic process that produces 3NADH molecules
now In the end we have 2 ATP and 2 NADH from glycolysis , just two NADH from link reaction and 2ATP,6 NADH with 2 FADH2 from two turns of Krebs cycle(for one glucose )
now all the ATP can be used to carry out tasks like stretching our muscles walking talking etc, but what about the NADH and FADH2 they are not the currency of our cell so to make them into ATP which is the currency of our cell they enter the electron transport chain in the mitochondrial membrane now in a series of complex reaction in the membrane of our mitochondria these NADH AND FADH molecules pass through certain complexes in the membrane. NADH involves complex 1 , 3,4 and finally the ATP synthase while FADH through complexes 1,2,4 and then ATP synthase now they don’t just simple pass on from one complex to another while doing so they pump protons (H⁺) from the inner mitochondrial matrix to the outer membrane by doing so there is an proton gradient created between the two membranes due to the deficit of protons on one side of the membrane thus because of this gradient the protons need to travel from the outer mitochondrial membrane back into the matrix this is acheived by the complex 5 or the ATP synthase which has two parts the F₀ and F₁ as the protons pass through the F₀ part (embedded in the inner membrane) and enter the F₁ part (projecting out of the membrane into the matrix) this causes the rotation of the c-ring and the γ (gamma) shaft this causes a series of steps and finally ATP is synthesized as the protons make their valiant comeback into the mitochondrial matrix . Now we have obtained useful energy but what happens to the NADH AND FADH molecules this is where oxygen comes in after donating the electrons which journey across the complexes these molecules become NAD⁺ and FAD⁺ molecules which are recycled in the body but what happens to the electrons after a rather tiring journey across the complexes their need in the body is over and we need someone or something to accept these electrons and this is precisly why we need oxygen at all (well primary case) O2​+4e−+4H+→2H2​O this reaction occurs where oxygen by accepting electrons is reduced into water molecule . in the absence of oxygen Electrons pile up in ETC ,NADH cannot become NAD⁺, Krebs cycle stops, Glycolysis stops, ATP production collapses and we evidently die but since we die within few seconds in abscence of oxygen is it essential for ATP synthesize to occur every second at all why we die within seconds can the already existing ATP be used for a little longer time period well if your thinking exactly this it is because ATP not stored like glucose or fat any moment, your body has ~50–100 grams of ATP total and we need it almost all the time thus even if the ATP machinery is halted for 30-60 seconds we experience irreversible brain damage loss of consciousness fatigue and eventually death.

NOW back to our question , if we can replace oxygen with perhaps another gas or even another molecule then there would essentialy be no need for oxygen but I researched a bit and identified potential candidates for the job firstly they have to be great in accepting electrons (good oxidizing agent better than oxygen) that’s the primary criteria , secondly they have to be non-toxic to the body other organs or part and viola that’s all pretty much concerning the physiological aspects we have a potent molecule which rules out the need for oxygen Oxygen is not special because it’s the strongest oxidizing agent.
It’s special because it hits a perfect balance. the redox potential of oxygen E∘≈+0.82 V High enough to pull electrons efficiently Low enough to not destroy biomolecules instantly other molecules stronger than oxygen like flourine and ozone are too strong Would rip electrons from everything in theory other alternates like nitrates and sulphates already used by bacteria could work but in reality they are hard and if we can come up with an effective way of making the body be immune and accept another gas

MARS has carbon dioxide , Venus has carbon dioxide and sulfur dioxide while Jupiter has hydrogen and helium which are almost impossible to replace oxygen while mars has a potential ability carbon dioxide is thermally unstable and not as efficient as oxygen

I would like to make my hypothesis that if we find a more promising oxidizing agent which is non toxic to our body breathable and accepted by our body without being toxic then we can definitley replace the need for oxygen. As we near the end of my first post I would like ponder on this:

“Is oxygen truly fundamental to life, or is it just the best solution evolution found?”