11/03/2009

The Chicken or the Egg

If the amino acid chain (call it protein) is coded by DNA, and if this process is maintain by proteins (enzymes) - so what was first? Proteins or DNA? It was the main problem in genetics and evolution. It was.
Imagine the molecule with both abilities: coding informations and being an enzyme. Is it possible? Off course it is. This molecule has been living for years in the shadow of DNA. Nowadays its rule is rising and it seems to be much more important than DNA. I am talking off course about RNA.
Imagine the world with RNA. No DNA, no proteins... Only RNA exist in the sea. This is a simple molecule. With only necessary genes. It is important to mention about environment. Because RNA is less stable than DNA. But in those days environment was different. Just to mention about oxygen... As we know, for sure, there was much, much less oxygen than nowadays. And other environmental components could be completely different.
But it can form double helix - like DNA. In those environmental conditions this helix could be much more stable. Imagine short RNA molecules which can replicate using its own catalyzing ability. The problem solved...

1 comment: