BIOL 215 Lecture Notes - Lecture 3: Cyanobacteria, Diatom, Digestion
Document Summary
Certain rna molecules can store information and acts as catalysts as well. Rna can be made to evolve to perform many functions. In an experiment, an rna was isolated from tetrahymena. Designed a system where variants of the ribozyme that were active with calcium were able to replicate whereas the magnesium variants were not (this is arti cial selection) After a while, the ribozymes were active with calcium instead of magnesium. Ribozyme produced in lab can synthesize rna of 14 nucleotides and template does not have to bind to ribozyme. Rna may have begun encoding proteins with catalytic properties. One of the enzymes may be reverse transcriptase (copies rna into dna) Dna is better for storing info since it is more chemically stable than rna. Final step in evolution must have been the formation of outer membranes that enclose nucleic acids and proteins. Nucleic acids and membranes eventually lead to the formation of a stable entity that displays cell behaviour.
