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What is AA in DNA?

Published in Genetic Code 2 mins read

In the realm of molecular biology and genetics, AA is a common abbreviation that stands for amino acid. Amino acids are fundamental organic molecules that serve as the building blocks of proteins.

Amino Acids and the Genetic Code

Proteins perform a vast array of functions within living organisms, and their specific function is determined by the unique sequence of amino acids that make them up.

The provided reference highlights a key aspect of this relationship:

  • It states that "only 20 amino acids occur in naturally derived proteins".
  • It also notes the existence of four key nucleotides in mRNA: adenine (A), uracil (U), guanine (G), and cytosine (C).
  • Crucially, the reference points out that these four unique bases in mRNA are responsible for coding for the 20 amino acids.

Connection to DNA

While the reference specifically discusses mRNA nucleotides (A, U, G, C) and their role in coding for amino acids, the genetic instructions for building proteins originate from DNA (deoxyribonucleic acid).

Here's how the process generally works:

  1. The sequence of nucleotides in a gene within DNA contains the instructions for a specific protein.
  2. This DNA sequence is transcribed into a messenger RNA (mRNA) molecule.
  3. The codons (sequences of three nucleotides) on the mRNA are then translated by cellular machinery into a specific sequence of amino acids, forming a protein.

Therefore, while the reference focuses on the mRNA stage of coding, the information stored in DNA ultimately dictates which amino acids are used and in what order they are assembled to create functional proteins. The abbreviation "AA" thus refers to these essential building blocks whose blueprint is stored in the DNA.