Let's create an alien biosphere!

[Schiaparelliorbust]

I know that humans turn recyclable amino acids into ammonia then turn the ammonia into urea. Bacteria probably do the same thing.

So it's done then? I mean them using nitrogen containing compounds.

[MathAndCode]

So it's done then? I mean them using nitrogen containing compounds.

I think that we already agreed that at least some creatures would.

[Schiaparelliorbust]

I think that we already agreed that at least some creatures would.

I mean have we figured out how life uses them?

[MathAndCode]

I mean have we figured out how life uses them?

We haven't completely. I'm sure that there will be more reactions.

[Schiaparelliorbust]

We haven't completely. I'm sure that there will be more reactions.

Do you have any suggestions?

[MathAndCode]

Do you have any suggestions?

Let's suppose that they evolve to store hydrogen cyanide as nitrile groups for later retrieval. Maybe this can lead to photosynthesis upstream of the hydrothermal vents.

[Schiaparelliorbust]

Let's suppose that they evolve to store hydrogen cyanide as nitrile groups for later retrieval. Maybe this can lead to photosynthesis upstream of the hydrothermal vents.

Why would they do that in the first place? Also, how would this lead to photosynthesis?

[MathAndCode]

Why would they do that in the first place?

in case hydrogen cyanide levels decreased temporarily

Also, how would this lead to photosynthesis?

Conjugated compounds are necessary for photosynthesis.

[Schiaparelliorbust]

Conjugated compounds are necessary for photosynthesis.

Ok. what happens next?

[MathAndCode]

Ok. what happens next?

Actually, I just checked, and the organisms upstream of the hydrothermal vents use isocyanic acid and formamide but not hydrogen cyanide. Should we find a energy-creating reaction that consumes hydrogen cyanide for them to use or see what we can do with isocyanic acid and formamide?

[Schiaparelliorbust]

Actually, I just checked, and the organisms upstream of the hydrothermal vents use isocyanic acid and formamide but not hydrogen cyanide.

Where did we say that?

Should we find a energy-creating reaction that consumes hydrogen cyanide for them to use or see what we can do with isocyanic acid and formamide?

I say the latter.

[MathAndCode]

Where did we say that?

in this post

I say the latter.

Isocyanate groups are also reactive. Perhaps the creatures can use those.

[Schiaparelliorbust]

Isocyanate groups are also reactive. Perhaps the creatures can use those.

Wikipedia says that they can be toxic, but I doubt that would be a serious problem for them. They can also be flammable.

[MathAndCode]

Wikipedia says that they can be toxic, but I doubt that would be a serious problem for them.

Yes, the organisms can just evolve to not be adversely affected by them.

They can also be flammable.

That means that they can be used as a source of energy.

[Schiaparelliorbust]

That means that they can be used as a source of energy.

Methyl isocyanate (MIC) is highly flammable. MDI and TDI are much less flammable.

Let's use one of the latter two. I don't want any potential creatures evolving from the unicellular organisms to be flammable.

[MathAndCode]

Let's use one of the latter two. I don't want any potential creatures evolving from the unicellular organisms to be flammable.

Earth-based organisms contain glucose, which is presumably flammable based on how much energy is released by oxidizing it, but they aren't prone to spontaneous combustion.

[Schiaparelliorbust]

Earth-based organisms contain glucose, which is presumably flammable based on how much energy is released by oxidizing it, but they aren't prone to spontaneous combustion.

Doesn't flammable mean prone to spontaneous combustion (or needing only a tiny spark to ignite)?

[MathAndCode]

Doesn't flammable mean prone to spontaneous combustion (or needing only a tiny spark to ignite)?

I think that spontaneous combustion from the inside is the only thing that we will need to worry about as the organisms now are all surrounded by water.

[Schiaparelliorbust]

I think that spontaneous combustion from the inside is the only thing that we will need to worry about as the organisms now are all surrounded by water.

I should have specified: any potential land-dwelling organism. There wouldn't be any pressure to not be spontaneously combustible in water, but if we find that they are so on land, it would be too late for us to change their chemistry.

[MathAndCode]

I should have specified: any potential land-dwelling organism. There wouldn't be any pressure to not be spontaneously combustible in water, but if we find that they are so on land, it would be too late for us to change their chemistry.

I don't think that that will be much of a concern. Life on Earth's land has managed to deal with fires.

[Schiaparelliorbust]

I don't think that that will be much of a concern. Life on Earth's land has managed to deal with fires.

Ok, I'll go with what you say. So should we figure out which specific isocyanate compound they use or not?

[MathAndCode]

Ok, I'll go with what you say. So should we figure out which specific isocyanate compound they use or not?

We don't need to do that, but we should figure out the general characteristics (e.g. whether or not the carbon backbone will be saturated, conjugated, or unsaturated but unconjugated).

[Schiaparelliorbust]

We don't need to do that, but we should figure out the general characteristics (e.g. whether or not the carbon backbone will be saturated, conjugated, or unsaturated but unconjugated).

I don't know enough chemistry to know what any of those properties would cause. Could you elaborate a bit?

[MathAndCode]

I don't know enough chemistry to know what any of those properties would cause. Could you elaborate a bit?

Conjugation would allow photosynthesis. Unsaturation is necessary for conjugation and would alter the chemistry even without conjugation.

[Schiaparelliorbust]

Conjugation would allow photosynthesis. Unsaturation is necessary for conjugation and would alter the chemistry even without conjugation.

I don't think we need photosynthesis now. Would unsaturation change it's reactiveness/energy output?