Codeine based biochemistry

[Ettina]

OK, in my story with a human colony ship headed to a new planet, I'm thinking of making the life on that planet originate from a comet carrying life with a shared ancestry to Earth life. Which means that they'll be a bit less alien than they otherwise could have been. They will share a lot of our amino acids, so people could eat them and actually gain nutrients.

However, I want a problem that makes the food dangerous to eat for all but a minority of the population. Since I'm immune to codeine, the idea I had was to have everything have high concentrations of codeine, so most people can only eat local life in moderation or risk overdose.

So my question is, how might an alien species (plantlike or animallike) use codeine in their biochemistry? What purpose would it serve, and what would be the likely concentration?

 

[fresh_42]

So my question is, how might an alien species (plantlike or animallike) use codeine in their biochemistry? What purpose would it serve, and what would be the likely concentration?

They definitely shouldn't have kidneys. And if, they won't have them for long.
$LD_{50} = 400\,mg\,kg^{-1} (rats), 60\,mg\,kg^{-1} (mice)$

To speculate on a hypothetical metabolism is rather difficult. What are your assumptions? As an alien life, you may invent whatever you like. If they are built similar to us, their lifespan would certainly be pretty short (kidney failure).

 

[jim mcnamara]

You would have problems 'basing' a metabolism on codiene. Our metabolism is based on photosynthesis to trap sun's energy. From there proteins, carbohydrates, and fats are generated in living cells using biochemistry - driven by the chemical energy that came from photosynthesis.

So you could say our biochemistry is based on the three primary building blocks of life. You could make codiene something that is used to store energy sort of like glycogen or starch do for us, if you want. Sort of like an oddball carbohydrate. Does that get at what you mean? I'm ignoring water to make it simpler.

 

[Algr]

They definitely shouldn't have kidneys. And if, they won't have them for long.

Hey Ettina, do you have kidneys?