After being produced, provides the blueprint for assembling proteins

The mRNA molecule is the blueprint for protein assembly in the processes described in the central dogma of molecular biology.
The process of translating the information in DNA to proteins happens in three steps.
Firstly, the DNA molecule replicates itself. 
After that one DNA strand (DNA is a double-stranded molecule)  transcribes itself into one-stranded messenger RNA (mRNA).
The information is held in the sequence of the nucleotides (Adenine, Cytosine, Guanine, Thymine) and it is read in triplets. So each mRNA is made from a sequence of nucleotides copied from the DNA, that is read in triplets.
Each triplet is holding the information about a specific amino-acid carried by transporter RNA (tRNA).
Proteins are made in the ribosomes in the process of translation, where the sequence on the mRNA is being read and translated into a sequence of amino acids.

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