Let's create an alien biosphere!

[MathAndCode]

The toxicity of cyanide is linked mainly to the cessation of aerobic cell metabolism. Cyanide reversibly binds to the ferric ions cytochrome oxidase three within the mitochondria. This effectively halts cellular respiration by blocking the reduction of oxygen to water.

Would this apply to creatures there or is there some way to prevent it or similar things from happening?

This isn't universal. If I recall correctly, most insects are not poisoned by cyanide because their electron transport chain is different.

[Schiaparelliorbust]

This isn't universal. If I recall correctly, most insects are not poisoned by cyanide because their electron transport chain is different.

CYANIDE toxicity is closely associated with respiratory inhibition and, in many forms of life, death is attributed to disruption of oxidative metabolism through inhibition of the enzyme cytochrome oxidase. In insects also, cyanide inhibits the terminal oxidase, and it has been shown that in the insect heart cyanide sensitivity is closely associated with aerobic metabolism.

Other sources also said that cyanide is poisonous to insects, but some have efficient mechanisms of getting it out of the body.

[MathAndCode]

Other sources said that cyanide is poisonous to insects, but some have efficient mechanisms of getting it out of the body.

I might be misremembering. However, I'm sure that it's possible for the creatures to evolve to not be poisoned by cyanide. Remember that most early life would have been poisoned by dioxygen (and was indeed poisoned by it when photosynthetic cyanobacteria started producing it), yet we can survive with 20% oxygen in the atmosphere.

[Schiaparelliorbust]

I might be misremembering. However, I'm sure that it's possible for the creatures to evolve to not be poisoned by cyanide. Remember that most early life would have been poisoned by dioxygen (and was indeed poisoned by it when photosynthetic cyanobacteria started producing it), yet we can survive with 20% oxygen in the atmosphere.

Yes. How would they do that exactly? You said that hydrogen cyanide is an oxidiser and Wikipedia says that it is a weak acid as well. Can they exploit these properties somehow? Also, what is the concentration of it and other stuff in the water?

[MathAndCode]

Yes. How would they do that exactly? You said that hydrogen cyanide is an oxidiser and Wikipedia says that it is a weak acid as well. Can they exploit these properties somehow? Also, what is the concentration of it and other stuff in the water?

They could use it as a source of nitrogen. They could use it as a signalling molecule. They could use it as a source of energy. They could attach nitrile groups in order to give conjugated systems or other biomolecules certain properties. Organisms can do many things with cyanide if they evolve to use it.

[Schiaparelliorbust]

They could use it as a source of nitrogen. They could use it as a signalling molecule. They could use it as a source of energy. They could attach nitrile groups in order to give conjugated systems or other biomolecules certain properties. Organisms can do many things with cyanide if they evolve to use it.

Then they would need to find a way for it not to inhibit cellular respiration. I think it binds to some enzyme that plays a key role in it. I don't want to get into too much detail but I think we should figure out how a cell there works.

[MathAndCode]

Then they would need to find a way for it not to inhibit cellular respiration. I think it binds to some enzyme that plays a key role in it. I don't want to get into too much detail but I think we should figure out how a cell there works.

They can just use different cytochromes. Cyanide doesn't bind to most cytochromes, so it's not universal. Also, if you're still confused about this, I recommend that you research coordination chemistry.

[Schiaparelliorbust]

They can just use different cytochromes. Cyanide doesn't bind to most cytochromes, so it's not universal. Also, if you're still confused about this, I recommend that you research coordination chemistry.

Ok, I trust you here. Should we also create systems for managing waste and reproduction? Maybe these cells could try and purify the water inside them by pumping out formamide.

[MathAndCode]

Ok, I trust you here. Should we also create systems for managing waste and reproduction? Maybe these cells could try and purify the water inside them by pumping out formamide.

That's possible, but early life would probably evolve to deal with a similar formamide:water ratio as the ocean that it formed in, considering the gradual nature in which life probably formed and the fact that early life probably wouldn't have anything complicated like formamide pumps. Also, having some formamide dissolved in the water may provide the organisms with some advantages, such as being less prone to freezing.

[Schiaparelliorbust]

That's possible, but early life would probably evolve to deal with a similar formamide:water ratio as the ocean that it formed in, considering the gradual nature in which life probably formed and the fact that early life probably wouldn't have anything complicated like formamide pumps. Also, having some formamide dissolved in the water may provide the organisms with some advantages, such as being less prone to freezing.

Yeah, you're probably right. Even if there was a clade that could pump out formamide, they would probably be outcompeted by those that can take advantage of it. What do you think about reproduction?

[MathAndCode]

Yeah, you're probably right. Even if there was a clade that could pump out formamide, they would probably be outcompeted by those that can take advantage of it. What do you think about reproduction?

For early life, I don't see a need to deviate too far from the mechanisms in the series. Also, I think that we should discuss the geology of the planet. What elements and minerals will be common in the crust?

[Schiaparelliorbust]

For early life, I don't see a need to deviate too far from the mechanisms in the series. Also, I think that we should discuss the geology of the planet. What elements and minerals will be common in the crust?

I don't really see any reason to change too much from Earth's unless you think that some other combination could yield something interesting. Also, by reproduction, I meant cellular reproduction. Will there be some organelles aiding the process or will it just simply be the membrane and cytoplasm splitting into two? I guess we can assume that they evolved some sort of DNA analogue too.

[MathAndCode]

I don't really see any reason to change too much from Earth's unless you think that some other combination could yield something interesting.

I just checked, and zeolite, which can catalyze the decomposition of formamide into water and hydrogen cyanide, occurs naturally on the seafloor in Earth. However, sulfur doesn't appear to be very abundant in Earth's crust, which I worry could hinder the ability of life that relies on sulfur for energy to prosper on land. Can we have sulfur be more abundant in this planet's crust?

[Schiaparelliorbust]

I just checked, and zeolite, which can catalyze the decomposition of formamide into water and hydrogen cyanide, occurs naturally on the seafloor in Earth.

Would the formamide be replenished somehow? We should probably figure out some cycle for it. Other than that, it sounds good to me for this planet.
Edit: Sorry, I forgot it was made with atmospheric gases.

However, sulfur doesn't appear to be very abundant in Earth's crust, which I worry could hinder the ability of life that relies on sulfur for energy to prosper on land. Can we have sulfur be more abundant in this planet's crust?

There is already hydrogen sulfide and sulfur oxides in the atmosphere. We could have it if you'd like though. Along with atmospheric chemotrophy as in Biblaridion's series, we could have "plants" that use the sulfur in the soil.

Off topic: Sorry I'm not online sometimes when you're online or I take a long time to respond. When you are online, it is usually a busier time of day for me.

[MathAndCode]

Would the formamide be replenished somehow? We should probably figure out some cycle for it. Other than that, it sounds good to me for this planet.

I figure that it can form from ammonia and carbon monoxide reacting in the atmosphere then will precipitate to the surface. Also, organisms might end up producing it.

There is already hydrogen sulfide and sulfur oxides in the atmosphere. We could have it if you'd like though. Along with atmospheric chemotrophy as in Biblaridion's series, we could have "plants" that use the sulfur in the soil.

Yes, but allowing plants to get sulfur from the soil has several advantages, such as being able to spend less energy on transporting the sulfur around the plant and not having to have as many open pores through which water can escape. Also, plants on Earth tend to do better in soil with a higher carbon content even though there is carbon in the atmosphere (in the form of carbon dioxide), and ditto for nitrogen. However, I just realized that the sulfur oxides in the air will likely react with the water to create sulfurous and sulfuric acid (which will be neutralized by the atmospheric ammonia), which will be brought to the surface by precipitation, so we don't have to worry so much about sulfates being in the ground to begin with but rather that the planet has sulfur that can get into the atmosphere. More active geology will help, and this will be caused by making the planet more massive, which I believe is already implied by the increased gravity, so we should be fine.



Edit: I just realized that even organisms whose overall energy-providing reactions reduce oxygen and oxidize carbon might benefit from using sulfur intermediates to reduce the amount of energy released by individual steps, which should make it easier to extract more energy to help power the organism's cellular processes.

[Schiaparelliorbust]

Yes, but allowing plants to get sulfur from the soil has several advantages, such as being able to spend less energy on transporting the sulfur around the plant and not having to have as many open pores through which water can escape. Also, plants on Earth tend to do better in soil with a higher carbon content even though there is carbon in the atmosphere (in the form of carbon dioxide), and ditto for nitrogen. However, I just realized that the sulfur oxides in the air will likely react with the water to create sulfurous and sulfuric acid (which will be neutralized by the atmospheric ammonia), which will be brought to the surface by precipitation, so we don't have to worry so much about sulfates being in the ground to begin with but rather that the planet has sulfur that can get into the atmosphere. More active geology will help, and this will be caused by making the planet more massive, which I believe is already implied by the increased gravity, so we should be fine.

We could maybe have some sort of mold-like multicellular clade that feeds primarily on sulfur in the soil. Also, sulfuric acid and ammonia will react to create ammonium sulfate, which is widely used as a fertilizer for alkaline soils on Earth.

Edit: I just realized that even organisms whose overall energy-providing reactions reduce oxygen and oxidize carbon might benefit from using sulfur intermediates to reduce the amount of energy released by individual steps, which should make it easier to extract more energy to help power the organism's cellular processes.

So sulfur might actually be necessary for life on this planet if it evolves very early on.

[MathAndCode]

We could maybe have some sort of mold-like multicellular clade that feeds primarily on sulfur in the soil.

Yes, that would be fine. I'd like to see some photosynthetic autotrophs use sulfur-including reactions for energy, though.

[Schiaparelliorbust]

We could maybe have some sort of mold-like multicellular clade that feeds primarily on sulfur in the soil.

Yes, that would be fine. I'd like to see some photosynthetic autotrophs use sulfur-including reactions for energy, though.

Ok, since we've got a rough layout for this planet, I think we should now evolve photosynthetic microbes. I guess we already had chemosynthetic ones. What color should they be?

[MathAndCode]

Ok, since we've got a rough layout for this planet, I think we should now evolve photosynthetic microbes. I guess we already had chemosynthetic ones. What color should they be?

I wouldn't worry about the color very much. On Earth, there are different colors of photosynthetic organisms due to absorbing different wavelengths of light, and the same will probably be true for the alien planet. What I do think we should concern ourselves with is deciding on the basic chemical reactions that the photosynthetic and chemosynthetic organisms use because that will likely influence the atmospheric chemistry.
Speaking of which, have we finalized the early atmosphere? This is my best idea of what it will be like:
50% dinitrogen
16% ammonia
15% carbon dioxide
6% sulfur oxides
5% carbon monoxide (in order for formamide to form)
2% hydrogen cyanide
1.5% methane
1.5% hydrogen sulfide
1% water vapor
0.6% ethane
0.5% sulfur oxyacids and oxyanions
0.4% isocyanic acid
0.5% trace gases

[Schiaparelliorbust]

I wouldn't worry about the color very much. On Earth, there are different colors of photosynthetic organisms due to absorbing different wavelengths of light, and the same will probably be true for the alien planet. What I do think we should concern ourselves with is deciding on the basic chemical reactions that the photosynthetic and chemosynthetic organisms use because that will likely influence the atmospheric chemistry.

We haven't actually talked about the star(s) this planet orbits. Are you okay with a red dwarf? It can last for literally trillions of years. Before we determine the type of star(s), it won't make much sense for us to talk about the wavelengths of light that photosynthetic life forms can use.

Speaking of which, have we finalized the early atmosphere? This is my best idea of what it will be like:
50% dinitrogen
16% ammonia
15% carbon dioxide
6% sulfur oxides
5% carbon monoxide (in order for formamide to form)
2% hydrogen cyanide
1.5% methane
1.5% hydrogen sulfide
1% water vapor
0.6% ethane
0.5% sulfur oxyacids and oxyanions
0.4% isocyanic acid
0.5% trace gases

That looks good enough to me. For now, the main thing that can change is probably only water vapor. We should probably figure out cycles for these substances. They will probably emerge naturally as we progress.

[HelicopterCat3]

They can simply evolve to tolerate it and even use it to their advantage. It can be useful as a building block for other biomolecules, and it can serve as an electron acceptor/oxidizing agent in certain contexts, which could be used to help drive exergonic reactions to power biological processes.

The toxicity of cyanide is linked mainly to the cessation of aerobic cell metabolism. Cyanide reversibly binds to the ferric ions cytochrome oxidase three within the mitochondria. This effectively halts cellular respiration by blocking the reduction of oxygen to water.

Would this apply to creatures there or is there some way to prevent it or similar things from happening?

Well, the solution to having creatures live in an environment of cyanide would be to have them 1. Have a cell wall (since cyanide breaks down the cellular membrane) and 2. Entirely rely upon a form of hyper-fermentation, like fermentation happening on a large scale able to provide the organisms with enough ATP (since cellular respiration can't happen). However, I don't know any organisms that do this since no organisms on Earth have needed to evolve to conditions with large amounts of cyanide. I know almonds have cyanide in them but that's different because almonds store them in the vacuoles of their cells.

And this is if we even want creatures in formamide-water mixture or if we even want a water-formamide mixture occurring at all

[Schiaparelliorbust]

Well, the solution to having creatures live in an environment of cyanide would be to have them 1. Have a cell wall (since cyanide breaks down the cellular membrane) and 2. Entirely rely upon a form of hyper-fermentation, like fermentation happening on a large scale able to provide the organisms with enough ATP (since cellular respiration can't happen). However, I don't know any organisms that do this since no organisms on Earth have needed to evolve to conditions with large amounts of cyanide. I know almonds have cyanide in them but that's different because almonds store them in the vacuoles of their cells.

And this is if we even want creatures in formamide-water mixture or if we even want a water-formamide mixture occurring at all

Can you please provide the source of where you learned that cyanide harms the cellular membrane? I only found this, but it's too technical for me to understand. Also, we're talking about hydrogen cyanide, so be careful. Fermentation can be useful, but if a clade of microbes can tolerate or even take advantage of the abundant formamide, they would take over. Aerobic respiration also allows for much more active lifestyles and probably consequently faster reproduction.

[HelicopterCat3]

Well, the solution to having creatures live in an environment of cyanide would be to have them 1. Have a cell wall (since cyanide breaks down the cellular membrane) and 2. Entirely rely upon a form of hyper-fermentation, like fermentation happening on a large scale able to provide the organisms with enough ATP (since cellular respiration can't happen). However, I don't know any organisms that do this since no organisms on Earth have needed to evolve to conditions with large amounts of cyanide. I know almonds have cyanide in them but that's different because almonds store them in the vacuoles of their cells.

And this is if we even want creatures in formamide-water mixture or if we even want a water-formamide mixture occurring at all

Can you please provide the source of where you learned that cyanide harms the cellular membrane? I only found this, but it's too technical for me to understand. Also, we're talking about hydrogen cyanide, so be careful. Fermentation can be useful, but if a clade of microbes can tolerate or even take advantage of the abundant formamide, they would take over. Aerobic respiration also allows for much more active lifestyles and probably consequently faster reproduction.

I learned it in a bio-chem class but I forget exactly what I read it from, so I'm probably wrong. Yes, yes, and yes. I never said that this kind of lifestyle for these organisms would be ideal, but certainly possible. I suppose a way it could break down the hydrogen cyanide is by separating the hydrogen with oxygen and turning them into hydroxide ions, but that would still leave the cyanide.
Also, it would be really hard for land creatures who need to drink water to live to deal with this.

[Schiaparelliorbust]

I learned it in a bio-chem class but I forget exactly what I read it from, so I'm probably wrong. Yes, yes, and yes. I never said that this kind of lifestyle for these organisms would be ideal, but certainly possible.

You're right. This sort of lifestyle is actually the only one possible before any photosynthesizers. I forgot that there was no oxygen. They could use sulfur as a weaker substitute though.

I suppose a way it could break down the hydrogen cyanide is by separating the hydrogen with oxygen and turning them into hydroxide ions, but that would still leave the cyanide.

For them to turn into hydroxide ions, there would also have to be something to become negatively charged. They could switch hydrogen ions with formic acid, but another thing that they could do is simply create H2 gas. I'm not sure if this is a viable reaction though, because my chemistry is terrible.

Also, it would be really hard for land creatures who need to drink water to live to deal with this.

By the time any land creatures evolve, they already would have gotten past any problems like that.

[MathAndCode]

We haven't actually talked about the star(s) this planet orbits. Are you okay with a red dwarf? It can last for literally trillions of years. Before we determine the type of star(s), it won't make much sense for us to talk about the wavelengths of light that photosynthetic life forms can use.

Photosynthetic organisms can use a variety of wavelengths of light. Phototrophs on Earth mainly absorb light in the visible spectrum only because that is the region of the electromagnetic spectrum in which the Sun emits the most light. Shorter wavelengths have more energy per photon, and hotter stars have a shorter average photon wavelength. An interesting idea would be to have two binary stars of different temperatures (and therefore different average photon wavelength) orbiting each other closely and to have a planet farther away orbiting both stars; this would result in the planet receiving a wider variety of electromagnetic radiation, which would give photosynthetic organisms more options. I don't think that a red dwarf would be a good idea because if the red dwarf is a single star, the habitable zone would be so close that the planet would become tidally locked, and if the red dwarf is a binary star, it would not contribute a significant proportion of light to result in photic diversity (unless the other star is also a red dwarf, in which case we have the same problem as with a single red dwarf).

That looks good enough to me. For now, the main thing that can change is probably only water vapor. We should probably figure out cycles for these substances. They will probably emerge naturally as we progress.

Volcanoes will emit sulfur compounds, carbon dioxide, and carbon monoxide into the atmosphere. The sulfur oxides produced with react with the water vapor in the air to produce sulfuric oxyacids, which will be neutralized by the ammonia to form sulfur oxyanions, which will then to to the surface via precipitation.
Formamide will be formed in the atmosphere from ammonia reacting with carbon monoxide and water reacting with hydrogen cyanide, be delivered to the surface via precipitation, and enter the oceans. At the bottom of the oceans, it will be converted by solid acid catalysts or heat from hydrothermal vents back into carbon monoxide and ammonia or into water and hydrogen cyanide. The first two of these compounds are gases at any temperature at which water is not solid (at least at standard pressure) and can only be dissolved in water in limited quantities, so they will reenter the atmosphere. The water will reenter the atmosphere through evaporation. Hydrogen cyanide would be liquid at the temperatures in most of Earth's ocean water, and it is miscible with water, but its vapor pressure is much higher than that of water, so it will evaporate into the atmosphere at a much greater rate that that of water. There will also be a reversible reaction where water and isocyanic acid interchange with ammonia and carbon dioxide. Isocyanic acid will be a similar case to hydrogen cyanide in the sense that its boiling point is near room temperature, and its vapor pressure is much higher than that of water (which is related to its lower boiling point), so it will enter the atmosphere from the oceans much more readily than water.



Edit: I'm considering reducing the percent dinitrogen to forty and scaling some other components up in order to compensate. Is that okay?