Chemistry of Alternate Lifeforms?

[Arcesious]

In the story I'm working on, I intend to be extremely detailed about pretty much everything. One thing I need help with is explaining the chemical compositions of different life forms. So, I could use the help of someone who knows a good deal about chemistry and its relation to biology to help me.

Firstly I need help explaining is the Zrzi species I mentioned. The chemical composition of said species that I already have includes: Bromine, Iron, Magnesium, Carbon, and Copper. What other elements would you think are needed to make this composition work for a life-form? (preferrably 'metallic' sorts of elements)

Secondly, for the Dalasians. Currently I have: Phosphorus, Magnesium, Methane, Nitrogen, Zinc, and Oxygen. What other elements would be needed to make this composition work for a life-form? (Preferably noble gases and 'hydraulic' elements that mostly tend to be mostly in a liquid form.)

And don't worry. It's science fiction, so if the chemical composition doesn't work, I can just make up some sort of psuedoscientific excuse.

[Hallucination]

Originally Posted by Arcesious

Secondly, for the Dalasians. Currently I have: Phosphorus, Magnesium, Methane, Nitrogen, Zinc, and Oxygen. What other elements would be needed to make this composition work for a life-form? (Preferably noble gases and 'hydraulic' elements that mostly tend to be mostly in a liquid form.)

You'll probably want to through some carbon or silicon in there, since carbon is the only element known to work as a base for life and silicon can in theory act as one.

Originally Posted by Arcesious

And don't worry. It's science fiction, so if the chemical composition doesn't work, I can just make up some sort of psuedoscientific excuse.

Sounds more like pseudoscience fiction to me.

[Wookiee Rrudolf]

You could use some hydrogen - the most common element in the universe
Also if you want to make life you will need some elements that can form long chains (like carbon does) to make some sort of proteins (or something similar).

Now in real life the only element that we know of that can form such chains is carbon (hydrocarbons) that connects it's atoms with other with C-C bonds. If you search more you'll find that other substances forming long chains don't have direct bonds between the same elements (except maybe for sulphur, but it's chains are quite short).

So, returning to your question:
1. Zrzi species: silicon and aluminium, they can form long chains. Silicon with oxygen: -Si-O-Si-O- that is glass and the three elements together: -Si-O-Al-O-Si-O-Al- forms a common rock but hey, it's science-fiction
2. Dalasians: phosphorous can exist in polymeric form on it's own (like sulphur - short chains) or in polyphosphate form -P-O-P-O-P- (polyphosphates with one, two and three P atoms are very important in human body, they form AMP, ADP and ATP - source of energy, P-O bond is high-energetic one).
Of course the chains that I wrote are not linear but ramified (it it's the correct word ). Hope that it helped a bit.

PS. If I was to write some sci-fi story I wouldn't mention biochemistry of alien life and left it a mystery Or if I had to for the sake of the story I would stick to good old carbon

[Arcesious]

Originally Posted by Wookiee Rrudolf

PS. If I was to write some sci-fi story I wouldn't mention biochemistry of alien life and left it a mystery Or if I had to for the sake of the story I would stick to good old carbon

Well I figure that starwars and star trek are such expansive and throughly explained sci-fi universes that my own universe will need some detail too. I just want to set up the life forms in my own sci-fi story so that they really are 'alien', and not what would be expected to be a form of life.

By the way, if there are any possible compounds of 'heavy' elements (atomic weight above 40) with 'medium' elements that can mimic the relationship of oxygen to hydrogen (atomic weight above 20), I'd like to use those if there are any. My intention is for the Zrzi to be Bromine-based (thus they are red in color), and the Dalasians to be Methane-based (thus being blue in color.)

[Wookiee Rrudolf]

Originally Posted by Arcesious

By the way, if there are any possible compounds of 'heavy' elements (atomic weight above 40) with 'medium' elements that can mimic the relationship of oxygen to hydrogen (atomic weight above 20), I'd like to use those if there are any.

I can't think of any... Water is really unique composition. But most of it's properties can be brought out of hydrogen bonding between molecules, so I guess that it would be possible to form a chemical composition that would act as water in some specific conditions (for example in extreme temperatures) made of some heavier elements.

[Hallucination]

Originally Posted by Arcesious

and the Dalasians to be Methane-based (thus being blue in color.)

Give them fairly transparent skin and copper-based blood (instead of iron), it makes more sense.

[machievelli]

Originally Posted by Arcesious

Well I figure that starwars and star trek are such expansive and throughly explained sci-fi universes that my own universe will need some detail too. I just want to set up the life forms in my own sci-fi story so that they really are 'alien', and not what would be expected to be a form of life.

By the way, if there are any possible compounds of 'heavy' elements (atomic weight above 40) with 'medium' elements that can mimic the relationship of oxygen to hydrogen (atomic weight above 20), I'd like to use those if there are any. My intention is for the Zrzi to be Bromine-based (thus they are red in color), and the Dalasians to be Methane-based (thus being blue in color.)

The only time explanations would be required is when they interact with others. One of my real negative views in this regard was a woman that was half human, and the other half a race that needed special assistance to survive in an oxygen atmosphere, the element being poisonous to them.

As for heavy metal, if you get too high they are toxic in concentration, both gold and nickel for example create toxic elements immersed in water