Membrane Self-Assembly Processes: Steps Toward the First Cellular Life by Pierre-Alain Monnard & David W. Deamer
Summary:
To summarize, early cells must have had a membrane to encapsulate its components and keep them within the cell. This membrane was made up of amphiphiles. This membrane was very permeable and as a result, passive diffusion occurred. Later on this membrane evolved to be a little impermeable as to keep the metabolic reactions and catalysts that drive these reactions within the cell. The membranes were also heterozygous in that it was made of more than one amphiphile. This characteristics accounts for the stability of the membrane itself. The early life forms also most definitely evolved in fresh water environments because of the …show more content…
This information is thought to have been RNA. Experiments to prove this, however, have shown to be complicated, since an RNA polymerase that is efficient enough to have been in the early life forms is yet to be found (RNA polymerase involves synthesizing new stretches of RNA). To counter this, experiments used other enzymes instead.
Now that an information system is intact, the life form can produce additional membrane surface so that the offspring can have sufficient amount of membrane when the cell is split into two. This splitting into two cells is called self-reproduction. In order for the cell to split, three things must be coded for: Transcription factors such as ribozymal polymerase, an enzyme to synthesize new membrane molecules from their components, and a budding RNA to split the membrane boundaries once it exceeds a certain surface area.
The conclusion was drawn that if the membrane formed exceeds the reproduction rates that is supposed to be formed, (as encoded by the genetic material) the new life form will lose some characteristics that the parents
Summary:
To summarize, early cells must have had a membrane to encapsulate its components and keep them within the cell. This membrane was made up of amphiphiles. This membrane was very permeable and as a result, passive diffusion occurred. Later on this membrane evolved to be a little impermeable as to keep the metabolic reactions and catalysts that drive these reactions within the cell. The membranes were also heterozygous in that it was made of more than one amphiphile. This characteristics accounts for the stability of the membrane itself. The early life forms also most definitely evolved in fresh water environments because of the …show more content…
This information is thought to have been RNA. Experiments to prove this, however, have shown to be complicated, since an RNA polymerase that is efficient enough to have been in the early life forms is yet to be found (RNA polymerase involves synthesizing new stretches of RNA). To counter this, experiments used other enzymes instead.
Now that an information system is intact, the life form can produce additional membrane surface so that the offspring can have sufficient amount of membrane when the cell is split into two. This splitting into two cells is called self-reproduction. In order for the cell to split, three things must be coded for: Transcription factors such as ribozymal polymerase, an enzyme to synthesize new membrane molecules from their components, and a budding RNA to split the membrane boundaries once it exceeds a certain surface area.
The conclusion was drawn that if the membrane formed exceeds the reproduction rates that is supposed to be formed, (as encoded by the genetic material) the new life form will lose some characteristics that the parents