[Zer0 (OP)]

Screenshot_20180605-020334.png (367.71 kB . 600x1024 - viewed 829 times)

Image Copyright & Credit - summitoxygen.com

[Kryptid]

Yes, it can exist without molecular oxygen (the gas that we need to survive). There are quite a few bacteria that are killed by it, in fact. On the other hand, all known life requires oxygen in the form of chemical compounds to survive. Vital molecules such as carbohydrates, nucleotides, proteins and, of course, water itself all contain oxygen.

[chris]

Indeed, as @Kryptid says, there are billions of bacteria doing exactly that inside you right now...

[evan_au]

Oxygen is the third most abundant element in the universe, regardless of whether you measure it as a fraction of atoms or a fraction of mass. Only Hydrogen and Helium are more common, and most of those atoms were created in the Big Bang.

Oxygen tends to be bound to other common elements like hydrogen (water), carbon (carbon monoxide/dioxide) and silicon (rock).
https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements#Universe

So to find life that didn't use oxygen in some form (even in the form of water or carbon dioxide), you would need to look in an environment that is highly refined with concentrated heavy elements.

One such environment might be an imaginary lifeform that existed at the boundary of the liquid and solid metallic core of the Earth. This environment is mostly iron and nickel. These metals are much denser than silicate rocks and tend to sink to the center of a (dwarf) planet. We can see samples of these substances in the form of iron meteorites.

See: https://en.wikipedia.org/wiki/Iron_meteorite#Chemical_classification

[RD]

Q. Can Life Exist without Oxygen?.

Life existed on Earth for more than a billion years years before oxygen appeared, see ...
https://en.wikipedia.org/wiki/Great_Oxygenation_Event
 

[CliffordK]

I suppose it depends on how one defines oxygen.

Plants have a complex respiratory cycle in which they take in carbon dioxide and excrete oxygen.  But, they may also reverse that process to some extent during the winter or at night.

But, carbon dioxide isn't without oxygen. 

So, molecules that contain oxygen include:

Oxygen (O₂), Carbon Dioxide (CO₂), Water (H₂O), and many basic carboxylic acids (HO-C=O group)

Take away all oxygen, and life on earth would not exist.  Not even intestinal bacteria, or the trees in your backyard.

To a large extent, sulfur will make many of the same compounds that oxygen does, so one could theoretically have sulfur based life instead of oxygen based life, but there would be problems with that.

Now, then comes the definition of "life".  It is inevitable that our computers will become smarter over time, perhaps to the point where they could be called life themselves.  Silicone based life?  Although, our computers may still depend on oxides.  Nonetheless, they could probably be built without oxides.

What if we send self-replicating, self-evolving smart probes to a distant planet?

And, we are just beginning to explore our universe.  We've been looking for life in the "Goldilocks zone", but that doesn't preclude very different forms of life.  For example, Jupiter may have a core of liquid/gas mixtures similar to Earth, but at very different temperatures, pressures, and with different chemical compounds.

Or, as evan_au mentioned, our Earth's core has heat, energy, and liquid..  many aspects that we find in life.  And we have yet to discover what really is down there. 

[mrsmith2211]

Anaerobic bacteria
https://medlineplus.gov/ency/article/003439.htm
Anaerobic bacteria are bacteria that do not live or grow when oxygen is present.

[Zer0 (OP)]

Subjective Answer - Yes.

Source:

https://news.nationalgeographic.com/news/2010/04/100416-oxygen-free-complex-animals-mediterranean/

http://www.bbc.com/earth/story/20170125-there-is-one-animal-that-seems-to-survive-without-oxygen



BUT keeping aside Oxygen(O2) and stretching the question further as to could life generate, survive & exist without any Oxides at all???

Was there life on Earth before the Great Oxygenation Event?
" The Great Oxygenation Event, the beginning of which is commonly known in scientific media as the Great Oxidation Event (GOE, also called the Oxygen Catastrophe, Oxygen Crisis, Oxygen Holocaust, Oxygen Revolution, or Great Oxidation) was the biologically induced appearance of dioxygen (O2) in Earth's atmosphere. Geological, isotopic, and chemical evidence suggest that this major environmental change happened around 2.45 billion years ago

Maybe, Cyanobacteria?
" Oceanic cyanobacteria, which evolved into coordinated (but not multicellular or even colonial) macroscopic forms more than 2.3 billion years ago (approximately 200 million years before the GOE), are believed to have become the first microbes to produce oxygen by photosynthesis. "

" By producing and releasing oxygen (as a byproduct of photosynthesis), cyanobacteria are thought to have converted the early oxygen-poor, reducing atmosphere into an oxidizing one, causing the Great Oxygenation Event and the "rusting of the Earth", which dramatically changed the composition of the Earth's life forms and led to the near-extinction of anaerobic organisms. "

Chemical Formulae for Photosynthesis
A simple word equation that can be used to describe the process of photosynthesis is carbon dioxide + water —> glucose + oxygen + water. A balanced chemical equation for the process can be written as 6CO2 + 6H2O —> C6H12O6 + 6O2. Overall, photosynthesis uses light energy to convert carbon dioxide into a carbohydrate.

That explains introduction of DiOxygen(O2) but an oxygen-poor environment does not mean that absolutely no O2 was present right? What about Oxides?

Anaerobic Respiration.
" Anaerobic respiration is a type of respiration that does not use oxygen. It is used when there is not enough oxygen for aerobic respiration. It can be summarised by the following equation: glucose → lactic acid (+ energy released) "

Chemical formulae for :
Glucose - C6H12O6
Lactic Acid - C3H6O3

What about Oxides?

Anaerobic Bacteria
" An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It may react negatively or even die if oxygen is present. "

Yes they don't use respiration/breathe.
Yes they don't require Oxygen, n some even die in its presence.
But then how do they generate survivable energy, Photosynthesis?
6CO2 + 6H2O —> C6H12O6 + 6O2

Oxides???

Life evolving & surviving in Deep Oceanic salty water in a pitch dark trench/valley without breathable Oxygen(O2) is still not good enough.
CF of Water - H2O = H(2) + O(1).

Hope in the future this could become a part of the Q.O.T.W or Q.O.T Month or Q.O.T Year, Decade or even Century.
Would love to listen to a Podcast (comments/explanations/views) by EXPERTS on the broader topic, could life evolve exist survive and thrive without any Oxides at all???

P.S. - Wonder what implications it would have on the search for Life elsewhere in the Universe and how Drake's Equation & Fermi's Paradox might have to be modified considering the answer for the question comes out to be a surprising YES.
✌

Acknowledgements & Thanks to
national geographic .com
bbc .com
Wikipedia
Google
TNS Members (for their respective opinions/views) 🙏
👍

[Kryptid]

BUT keeping aside Oxygen(O2) and stretching the question further as to could life generate, survive & exist without any Oxides at all???

Given that water is an oxide, the answer appears to be no. For Earth-based life at least.