Answer and Explanation:
These are used to construct a protein (or other functional product). How are the instructions for building a protein encoded in DNA, and how are they deciphered by the cell? In this article, we'll take a closer look at the genetic code, which allows DNA and RNA nucleotide sequences to be translated into the amino acids they represent.
Overview: Gene expression and the genetic code
Genes that provide instructions for proteins are expressed in a two-step process.
In transcription, the DNA sequence of a gene is "rewritten" using RNA nucleotides. In eukaryotes, the RNA must go through additional processing steps to become a messenger RNA, or mRNA.
In translation, the sequence of nucleotides in the mRNA is "translated" into a sequence of amino acids in a polypeptide (protein or protein subunit).
Cells decode mRNAs by reading their nucleotides in groups of three, called codons. Each codon specifies a particular amino acid, or, in some cases, provides a "stop" signal that ends translation. In addition, the codon AUG has a special role, serving as the start codon where translation begins. The complete set of correspondences between codons and amino acids (or stop signals) is known as the genetic code.
