Translating the Genetic Message

Protein biosynthesis is a complex process requiring ribosomes, messenger RNA (mRNA), transfer RNA (tRNA), and a number of protein factors. The ribosome is the site of protein synthesis. The mRNA and tRNA, which are bound to the ribosome in the course of protein synthesis, are responsible for the correct order of amino acids in the growing protein chain. 

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Transfer RNA brings amino acids to the site at which they are incorporated into a growing polypeptide chain. 

Protein translation involves three types of RNA and many protein factors. 

Amino acids are activated via enzymes called aminoacyl-tRNA synthetases. 

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Translation—the process by which the genetic messages are decoded and used to synthesize proteins... 

Nucleic acids comprise an important category of drug receptors. A number of antibiotics and antirnmor agents either interfere directly with DNA replication or transcription, or inhibit translation of the genetic message at the ribosome level. Certain steroid hormones may also have DNA as their acceptor site (see chapter 8). 

Translation The process by which information is transferred from RNA to protein structure. See Ochoa, S., Translation of the genetic message. Bull. Soc. Chim. 

The codons of mRNA must be read if the genetic message is to be translated into protein. The molecule that decodes the information in the mRNA molecule into the primary structure of a protein is transfer RNA (tRNA). To decode the genetic message into the primary sequence of a protein, the tRNA must faithfully perform two functions. 

Three major types of RNA are found in cells--ribosomal RNA (rRNA), transfer RNA (tRNA), and messenger RNA (mRNA). They function in ribosome structure/fimction, translating the genetic code, and carrying the message to be translated, respectively. mRNA is a small percentage of total cellular RNA (1% to 3% in bacteria). 

Chapter 27 covers the chemistry and structures of nucleosides, nucleotides, and nucleic acids (RNA and DNA). You will see—mechanistically—why ATP is the universal carrier of chemical energy, how nucleotides are liked to form nucleic acids, why DNA contains thymines instead of uracils, and how the genetic messages encoded in DNA are transcribed into mRNA and then translated into proteins. Also explained are how the sequence of bases in DNA is determined and how DNA with specific base sequences can be synthesized. 

Translation is the process by which the genetic message in DNA that has been passed to mRNA is decoded and used to build proteins. Each of the approximately... 

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