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
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
Six major differences are:
- The sugar in the RNA molecule is ribose. DNA's
sugar is deoxyribose.
- RNA is usually a single stranded molecule
while DNA is nearly always double stranded.
- 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
- RNA uses the nucleotide uracil instead of
- DNA is often 103 to 106
times larger than RNA
- RNA is much less stable than DNA. As a single
stranded molecule it has no way of reparing itself.