Lecture - Genes in Action

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The Central Dogma 

All life all cells make proteins. DNA cannot produce proteins directly. The molecule which acts as a bridge between DNA and the proteins which it codes for is RNA. The flow of information from DNA to RNA to Protein is known as the Central Dogma

Comparing DNA to RNA

RNA is a more versitle molecule than DNA. It is able to store and code for information or act as a catalyst. RNA however is less stable than DNA -- subject to degredation or mutation.

Six major differences are:


  1. The sugar in the RNA molecule is ribose. DNA's sugar is deoxyribose.
  2. RNA is usually a single stranded molecule while DNA is nearly always double stranded.
  3. DNA's rigid double helix structure allows for only one function (information storage) whereas RNA's greater molecular diversity results in a wider range of functions
  4. RNA uses the nucleotide uracil instead of thymine
  5. DNA is often 103 to 106 times larger than RNA
  6. RNA is much less stable than DNA. As a single stranded molecule it has no way of reparing itself.