Why all the shells and skeletons are made from calcium carbonate, why not something else?

[Pretty_Girl]

Why all the shells and skeletons are made from calcium carbonate (CaCo3), why not something else? why not C₂H₃Cl or C₂H₄O or something else?

What is the reason? why it wasn't something else? this is an inorganic chemistry related question. This baffles me. when we see living things all of them have caco3 in them. why?

why couldn't it be something else that gives similar strength or may be more strength?

 

Edited March 24, 2020 by Pretty_Girl

[marmle]

I'm no expert,  but I would put it down to evolution,  its just the way things happened.  All living things are carbon based,  so it was bound to have a carbon component of some sort. There probably are better materials but evolution is a slow process and it will take a long time before nature "finds" a better alternative, and since calcium carbonate has been the material of choice for so long,  I don't think it will change ever to be honest.

Most living things are at the chemical process level more complicated than they need to be with several processes needed to carry out a simple task, its just the way things evolved.

Edited April 17, 2020 by marmle

[studiot]

21 minutes ago, marmle said:

Most living things are at the chemical process level more complicated than they need to be with several processes needed to carry out a simple task, its just the way things evolved.

Not really, I think it was Einstein who said something about  complication.

Quote

Einstein

"Everything should be made as simple as possible, but not simpler"

Calcium is a very good substance, entirely fit for purpose, but not the only one involved, either chemically or biologically.

Did you know that 'bone' is a form of living tissue?

[marmle]

3 minutes ago, studiot said:

Einstein

"Everything should be made as simple as possible, but not simpler"

I like that!

[Strange]

On 3/24/2020 at 3:15 PM, Pretty_Girl said:

Why all the shells and skeletons are made from calcium carbonate (CaCo3), why not something else? why not C₂H₃Cl or C₂H₄O or something else?

Bones are mainly hydroxyapatite, which is an insoluble salt of calcium and phosphorus. There are also other mineral compounds and various proteins. As studiot says, it is a living tissue, with cells that continuously break down old bone tissue and others that constantly make more (there are various diseases where one or other of these go wrong). 

Bone is also an important organ, acting as a reservoir of minerals the body needs and a place where blood cells a re made.

Shells are mainly calcium carbonate. 

Calcium has the useful property that some of its compounds are soluble, making it readily available to organisms to use. But other compounds are insoluble and, in some case, very hard. There is also a lot of it about; it is the fifth most common element on Earth.

 

[Endy0816]

Many also make use of metastable Argonite form of calcium carbonate instead of, or in addition to, Calcite. Rather impressive really, takes higher pressures to occur via physical processes.

https://en.m.wikipedia.org/wiki/Aragonite

Edited April 17, 2020 by Endy0816

[Ken Fabian]

Not all shells are calcium carbonate. Radiolaria and Diatoms as counter examples, make their shells/skeletons out of Silica - SiO2.