Transcription and Translation

307 Words2 Pages
Synthesis of polypeptide chains is protein The chains produce specfic proteins based on the genetic code in DNA. This occurs in two stages, which is transcription and translation. The transcription stage occurs in the nucleus where the DNA contains the cistrons/genes that code for specific polypeptides. The transcribing stand is the part of the strand that forms the cistron. The strand acts as a template and is transcribed to mRNA. The strand that does not carry cistron is called a non-transcribing strand. An enzyme RNA polymerase attaches itself to the promoter site next to the cistron on the DNA. This triggers the start of transcription. The enzymes move around the DNA section. Corresponding bases with nucleotides from the nucleoplasm and bases on DNA are added one at a time to extend the strand. This is when base pairing occurs. For example, base adenine on DNA pairs with uracil nucleotide and base cytosine will pairs with guanine nucleotide. Codons in mRNA are used to assemble amino acids in the correct sequence to produce a polypeptide chain, which is the process of translation. mRNA binds to the binding site on the smaller ribosomal subunit and tRNA carries amino acids to the ribosome. Cells contain more than twenty types of tRNA, which is more than enough for different amino acids.The codon of mRNA forms hydrogen bonds with the anticodon of tRNA.The tRNA goes back to the cytoplasm to create more amino acids after detching itself from mRNA.Peptide bonds are created between neighboring amino acids, forming a polypeptide chain. rRNA consists of a single polynucleotide strand synthesised in the nucleus. The rRNA form mixes with proteins to form the large and small subunit. The subunits then leave the nucleus from the nuclear pore and head into the cytoplasm. The subunits combine to make a

More about Transcription and Translation

Open Document