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Next: Transfer RNA Up: 11. Nucleic Acids Previous: 11. Nucleic Acids

Biology of DNA

1. Replication. When the two strands are separated, the single strands can act as templates for the enzyme-mediated formation of complementary strands.

2. Transcription. The genetic information of DNA is transferred to RNA molecules which act as the primary templates that cause the organization of amino acid sequences in proteins. Complementary base pairs are formed as a DNA strand is copied to give the messenger RNA template for protein formation.

3. Protein synthesis. A specific adaptor, transfer RNA, combines with both the RNA and amino acid, mediating the polymerization of amino acids. Each amino acid has a different transfer RNA which recognizes it and interacts with it by a process called `activation'. This is effected by a specific enzyme (amino-acyl synthetase), specific for each amino acid. After activation, the amino acid-transfer RNA complex diffuses to the ribosomes where messenger RNA is attached and protein synthesis results.



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