Humans Are Designated as Carbon Based Lifeforms

I have a question about that subject line above...

I learned in school (many, many yrs ago now) that humans are considered by the scientific community to be carbon based life forms.

The human body is made up of mostly water... (varies from 60% to 70% individually)

So, why does the science community not classify us humans as "water based life forms"? It just makes more sense to me but I am not a scientist.

ThoughtCo Website - Composition of the Human Body

From the website:
"Water: Water is the most abundant chemical compound in living human cells, accounting for 65 percent to 90 percent of each cell. It's also present between cells. For example, blood and cerebrospinal fluid are mostly water."

Excerpt from: openstax.org...
"A nutrient is a substance in foods and beverages that is essential to human survival. The three basic classes of nutrients are water, the energy-yielding and body-building nutrients, and the micronutrients (vitamins and minerals).

The most critical nutrient is water."

It certainly seems to me that our species is due for a reclassification, as well as the majority of life on planet Earth.

a reply to: repairguyt

Because the proteins that make up the majority of the structures that allow us to be humans, are built on many different combinations of carbon molecules.

a reply to: repairguyt


Water (H2O) is a chemical compound.


Carbon is an Element.


"Elements", in the scientific usage, are irreducible into constituent chemical components. Carbon forms the basis of the multitude of the chemical conversions and processes that power the body's life functions.

a reply to: repairguyt


Humans are called "carbon-based lifeforms" because carbon is the primary element in the molecules that form the basis of our biology. Though we are mostly composed of water, it is the carbon-containing molecules that define our life processes.

I know this is stupid, but do you think in the future people will say they are silicon lifeforms just because that is how they feel?... I feel bad just for saying that...

a reply to: TheUniverse2

Myself, I identify as photonic.

Off topic, but Carbon Based Lifeforms is one of my fav bands. May I recommend the albumn World of Sleepers

originally posted by: repairguyt
I have a question about that subject line above...

I learned in school (many, many yrs ago now) that humans are considered by the scientific community to be carbon based life forms.

The human body is made up of mostly water... (varies from 60% to 70% individually)

So, why does the science community not classify us humans as "water based life forms"? It just makes more sense to me but I am not a scientist.

ThoughtCo Website - Composition of the Human Body

From the website:
"Water: Water is the most abundant chemical compound in living human cells, accounting for 65 percent to 90 percent of each cell. It's also present between cells. For example, blood and cerebrospinal fluid are mostly water."

Excerpt from: openstax.org...
"A nutrient is a substance in foods and beverages that is essential to human survival. The three basic classes of nutrients are water, the energy-yielding and body-building nutrients, and the micronutrients (vitamins and minerals).

The most critical nutrient is water."

It certainly seems to me that our species is due for a reclassification, as well as the majority of life on planet Earth.

I found out we were carbon based lifeforms when Darth Vader froze Han in the Empire strikes back
Though that wasnt the part of the film that truly freaked me and my mates out haha

originally posted by: TheUniverse2
I know this is stupid, but do you think in the future people will say they are silicon lifeforms just because that is how they feel?... I feel bad just for saying that...

No, because they don't have silica atoms as a main component of their DNA/RNA.

originally posted by: repairguyt
I have a question about that subject line above...

I learned in school (many, many yrs ago now) that humans are considered by the scientific community to be carbon based life forms.

All life forms are "carbon based" in that the material that differentiates a living thing from a not-living thing (like a rock) is the presence of complex compounds that are all based around carbon. (called "carbon compounds" because they're compounds that have carbon chains or rings in them. Or carbon, for that matter.)

Even viruses have a nucleic compound that acts like DNA/RNA. Basic energy exchange processes (like the citric acid metabolic cycle) revolve around a carbon compound.

H2O is not present in every compound in your body (stomach acid, which is HCl, certainly doesn't have water in it.) You may have hydrogen and oxygen in a polymer in your body, but it won't be in the form of "H20".

Water in your body doesn't float around as water (as a rule). It's just one of many compounds.

Nevermind

originally posted by: TheUniverse2
I know this is stupid, but do you think in the future people will say they are silicon lifeforms just because that is how they feel?... I feel bad just for saying that...

Depending on your age, you might have seen a Star Trek episode where Spok does a mind-meld with a silicon-based lifeform. Come to find out, it was in pain and severely misunderstood by the planet's resident humanoids. I don't remember how old I was but it's when I discovered humans are carbon-based. The things I learned from Star Trek!

Others above have already touched on why Carbon is central, but I want to add a few more keywords.

(I'm not a chemist, but I did sleep at a Motel-6 last night.)

Chemistry: the 2 big divisions of this field of study are: Organic and Inorganic.

Organic Chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.

...and Inorganic Chemistry is pretty much everything else (non-carbon-based).

Carbon (#6) is interesting, because it has ±4 valence -- which is to say it has 4 receptive bonding points (electron orbitals). By default, these are arranged in 3-dimensional space like the points of a tetrahedron, so Carbon can be the basis of 3-dimensional molecules. Furthermore, these bonds have goldilocks strength: not too weak, not too strong... just right, and the molecules have good stability.

(Nitrogen (#7: +5/-3 valence) can form similar molecular shapes, but the molecules are unstable. The majority of chemical explosives are based on nitrogen-compounds.)

(Oxygen (#8: +6/-2) can really only form planar constructs, but it is "highly reactive", which is to say it is so greedy to bond with other elements, that it will rip other molecules apart in order to neutralize its -2 valence -- this process is called Oxydizing or Burning.)

Note to self: don't reincarnate as Nitrogen or Oxygen based lifeform -- were such even stable enough to evolve "life".

(Fluorine (#9: -1) has even higher bond-strength than oxygen. Most of the "Forever Chemicals" incorporate Fluorides of some sort - the bonds in some cases have no expected expiration date: once created, they are permanent pollution.)

Chemistry happens better at parties where drinking is involved: water (the "universal solvent") just happens to be abundant, liquid across a convenient range of temperatures, and able to dissolve many many organic and inorganic compounds - to create just the sort of gatherings and interminglings that can lead to interesting chemical reactions. The so-called "primordial-soup" is a heady broth of organic compounds.

All Life As We Know It (LAWKI) is based on the same ingredients, and basic molecular-reaction pathways. It is hypothesized by many (by whom? citation needed.) that LAWKI is all related and descended from one organism: the Last Universal Common Ancestor (LUCA).

Theorists of Alternative Biologies and/or Exobiologies (that we may encounter someday if we ever get off this rock), speculate in several different ways about Life As We Don't Know It, but can Imagine It:

The next best choice after carbon, on which to found a new branch of "pseudo-organic" chemistry is Silicon: it's right under Carbon in the Periodic Table, so it shares many properties: ±4 valence... but unfortunately, like Boron, it's a semi-metal : better suited to making semiconductor electronics (as we do) than to being the backbone of flexible and interesting molecules. Even so, Silicon is still the 2nd best choice after Carbon.

Swapping out water for some other solvent has also been theorized. Ammonia NH3 is a common suspect, because it is a good solvent, liquid and "room temperatures" (as if that matters on universal scales).

--- there is a moderately famous single-frame cartoon, by R.Grossman, ©1962, first published in the New Yorker Magazine, in which we see a crashed flying saucer, and an alien crawling away with tongue hanging out, past a saguaro cactus under a baking desert-sun. Caption reads: "Ammonia! Ammonia!"

Breathing Oxygen is overrated, so that too is up for alternatives.

These speculations generally assume temperatures and pressures similar to what we are used to. The chemical possibilities are greatly expanded when we start imagining conditions at either 1000°C warmer, or under tremendous pressures. What could "live" on Titan, Jupiter, in the frozen oceans of Jupiter's moons, or in the clouds of Venus. Different conditions change the possibilities for common chemical reactions.

Have to say something about CHON (Carbon Hydrogen Oxygen Nitrogen (PS: Phosphorous Sulfur)) : just these 6 elements make up something like 96% of the weight of a human (as a proxy for Life As We Know It).

When the WEF talks about a zero carbon future they are definitely saying humans are carbon based life forms. You will own nothing (not even your life) and you will be happy (the dead are always in bliss, right?).

originally posted by: Byrd
originally posted by: TheUniverse2
"I know this is stupid, but do you think in the future people will say they are silicon lifeforms just because that is how they feel?... I feel bad just for saying that..."

No, because they don't have silica atoms as a main component of their DNA/RNA.

If that was true, then wouldn't not having a vagina and ovaries stop men from identifying as women?
What about the little actor in the Star Trek episode whose mother died and he buried his emotions and pretended to be an android instead of a human, so he didn't have to deal with his emotions? Trying to convince that boy he wasn't an android was almost as hard as trying to convince some men they aren't really women. Though I'm ok with men feeling like women and dressing however they want, I'm just saying that doesn't change their DNA, and feeling like an android run by silicon doesn't mean you're no longer a carbon-based human.

originally posted by: LogicalGraphitti
Depending on your age, you might have seen a Star Trek episode where Spok does a mind-meld with a silicon-based lifeform. Come to find out, it was in pain and severely misunderstood by the planet's resident humanoids. I don't remember how old I was but it's when I discovered humans are carbon-based. The things I learned from Star Trek!

ArMaP made a thread about how so-called "AI" or artificial intelligence is not really intelligent yet. But some day, it might be, and then if it's based on the silicon chips that make up today's or the future's computers, then would that sort of be a silicon-based life form? Sort of like Commander Data, if you are a star trek fan?

We are already sending semi-intelligent robots based on silicon "intelligence" to Mars that can inspect the terrian and drive remotely to avoid obstacles without an operator's direct live input (the time delay is too long), and I'm sure we will send even more intelligent probes in the future. For all we know aliens could be sending silicon-based probes to Earth, though I'm highly skeptical of claims by David Grusch when he either believes old wives tales like the Italy UFO, or wants us to believe he does.

originally posted by: Arbitrageur
If that was true, then wouldn't not having a vagina and ovaries stop men from identifying as women?

I believe you posted in the wrong thread. This particular thread is about organic chemistry.

What about the little actor in the Star Trek episode whose mother died and he buried his emotions and pretended to be an android instead of a human, so he didn't have to deal with his emotions? Trying to convince that boy he wasn't an android was almost as hard as trying to convince some men they aren't really women. Though I'm ok with men feeling like women and dressing however they want, I'm just saying that doesn't change their DNA, and feeling like an android run by silicon doesn't mean you're no longer a carbon-based human.

No, really. This is about organic chemistry and why we're considered "carbon based life forms". tnxoxodka gave a WONDERFUL answer about 3 posts above this one. You should read it.

We are already sending semi-intelligent robots based on silicon "intelligence" to Mars that can inspect the terrian and drive remotely to avoid obstacles without an operator's direct live input (the time delay is too long), and I'm sure we will send even more intelligent probes in the future.

They're not intelligent... and all computer chips are silicon based. Computer chips aren't alive, either.

Carbon is one of the few atoms that can form long chains of itself it is called catenation. Bond strength gives a lot of opportunity to form complex molecules. That is probably why carbon was the choice of nature for life. Silicon not so flexible.