protein catalysts and ribozymes
BIO.COM: Biotechnology & Pharmaceutical News, Jobs, Software, Reports, Books, Events: "Protein enzymes are polymer strings made up of the 20 different amino acid building blocks, many of which have reactive side chains that can participate in biocatalysis. RNA polymers are made up of only four different building blocks, the RNA nucleotides, which lack the chemical versatility and reactivity of the protein functional groups.
After the discovery that RNA could act as a biocatalyst, many scientists began to theorize and discuss the possibility of an RNA world, the notion that at one time the world was ruled by RNA-based life forms in which RNA enzymes were the chief catalytic molecules and RNA nucleotides were the building blocks that stored genetic information. This raised a number of questions, such as where catalysis came from and how the world transitioned from an RNA-based form to the current DNA-RNA-protein form."
After the discovery that RNA could act as a biocatalyst, many scientists began to theorize and discuss the possibility of an RNA world, the notion that at one time the world was ruled by RNA-based life forms in which RNA enzymes were the chief catalytic molecules and RNA nucleotides were the building blocks that stored genetic information. This raised a number of questions, such as where catalysis came from and how the world transitioned from an RNA-based form to the current DNA-RNA-protein form."