Describe the stages in DNA transcription and translation

DNA is unziped by DNA helicase. RNA polymerase catalyses the formation of a complementary strand of pre-mRNA, using the non-coding strand of DNA as a template. The pre-mRNA contains non-coding regions (introns) which are removed through splicing to form mature-mRNA. As the mRNA is single stranded, it can leave the nucleus via the nuclear pores and bind to a ribosome on the rough endoplasmic retIculum (rER). Starting with the 'start' codon, each codon on the mRNA sequence is read in order. The amino acid which corresponds with each codon is carried by a tRNA to the ribosome. Adjacent amino acids form peptide bonds which results in the formation of a long chain of amino acids, or a polypeptide.