Chapter 4 - Gene expression: translation of the genetic code

Abstract

The second stage of gene expression is translation, in which the mRNAs serve as the template for making the critical cellular molecules: proteins. This process is also known as protein synthesis. The ability of all living organisms to efficiently and accurately translate genomic information into functional proteins is a remarkable process. Protein synthesis is a complex process requiring ribosomal RNA, messenger RNA, transfer RNA, and a number of regulatory proteins. After translation, newly synthesized proteins are subject to posttranslational modification to become biologically functional. Like DNA and RNA, proteins are polymers—long, chain-like molecules. The monomers in the protein chain are called amino acids. The informational relationship between DNA and protein is determined by the genetic code, which is a three-nucleotide code. Each genetic code determines an amino acid and thus, the protein. In this chapter, we introduce the amino acids and protein structures. The mechanism of translation and posttranslational modifications are also discussed in this chapter.