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I believe the point is more from a relatively "simple" molecule you can have catalytic reactions that don't require metal or complex protein systems. When appli

I believe the point is more from a relatively "simple" molecule you can have catalytic reactions that don't require metal or complex protein systems. When applied to the observation about life means that random organic compounds could have started selective catalytic reactions which could have given rise to more complex systems which then give rise to the building blocks of life or something. This is me speculating on the meaning of the original comment, my knowledge of abiogenesis is lacking and I know RNA can do some enzymatic reactions which are also organic compounds.

gilleain 5y ago
That makes sense, thanks. With regards to abiogenesis, that is a wonderful area for wild speculation. I say that having done a tiny bit of that myself :) Certainly it would be helpful to have small-molecule catalysts to bootstrap life into having polymer catalysts. I just do not think it matters much about excluding metals, since there were bound to be sufficient dissolved metal ions floating around. Of course, whether they were the 'right' metals and in a suitable oxidation state and so on is a different question.
- siver_john 5y ago
  I think the importance of organocatalysts besides being potentially less "harsh" is that they can also be more selective in what reactions they allow, which would be important in getting to those polymers. For example most of the amino acids in biology are L-enantiomers. So the reaction in the primordial soup would require catalysts which would bias towards that specific shape, where as a metalocatalyst may be less specific and generate both the L and R enantiomers at equal or near equal rate. Also it could also be that metalocatalysts generate side products at a higher rate such that it consumes say some of your amino acids unhelpfully. So you may be able to think about it as an intermediate step of metals->organocatalysts->polymer catalysts. Full Disclosure: Am not a chemist but work with chemists, one of which follows MacMillan closely. And have sat through a lot of presentations looking at how different catalysts affect selectivity of products.

gilleain 5y ago

That makes sense, thanks. With regards to abiogenesis, that is a wonderful area for wild speculation. I say that having done a tiny bit of that myself :) Certainly it would be helpful to have small-molecule catalysts to bootstrap life into having polymer catalysts. I just do not think it matters much about excluding metals, since there were bound to be sufficient dissolved metal ions floating around. Of course, whether they were the 'right' metals and in a suitable oxidation state and so on is a different question.

siver_john 5y ago
I think the importance of organocatalysts besides being potentially less "harsh" is that they can also be more selective in what reactions they allow, which would be important in getting to those polymers. For example most of the amino acids in biology are L-enantiomers. So the reaction in the primordial soup would require catalysts which would bias towards that specific shape, where as a metalocatalyst may be less specific and generate both the L and R enantiomers at equal or near equal rate. Also it could also be that metalocatalysts generate side products at a higher rate such that it consumes say some of your amino acids unhelpfully. So you may be able to think about it as an intermediate step of metals->organocatalysts->polymer catalysts. Full Disclosure: Am not a chemist but work with chemists, one of which follows MacMillan closely. And have sat through a lot of presentations looking at how different catalysts affect selectivity of products.