Describe the role of DNA in protein synthesis

Protein synthesis is dependant of the DNA being properly decoded. To start the process of protein synthesis a section of the DNA “ unzips “ exposes the base sequence on the decoding strand. However, DNA is too large a molecule to pass through the nucleus wall into the cytoplasm where the protein is made. This means that the DNA has to be copied and transported through into the cytoplasm. This is done by messenger RNA.

Once the DNA has unzipped messenger RNA (mRNA) from the cytoplasm comes into the nucleus and attaches itself to the DNA. Whilst doing this it makes sure that the organic bases match up: adenine to uracil and guanine to cytosine. This is in accordance to the rules of organic base pairing. Once the mRNA has copied the DNA it floats of into the cytoplasm through the nuclear pores. This process is called transcription.

Once the mRNA has passed through to the cytoplasm it attaches its self onto a ribosome or rRNA. This is the RNA that allows the mRNA to be separated into codons. Codons are three bases of the mRNA. Each codon once translated will mean a certain amino acid is added to the ribosome. Anther type of RNA is needed to translate the codons. They are called transfer RNA (tRNA). They are made up of three organic bases called anticodons. Each transfer RNA attaches its self to the relevant codon so the organic bases match adenine to uracil and guanine to cytosine. This process is called translation.

Each tRNA has a specific amino acid attached to it.  Once the tRNA has attached to the relevant codon the amino acid floats of and attaches to the ribosome. Then the ribosome moves down to the next codon and another tRNA comes with a different amino acid. This amino acid then floats of and attaches to the other amino acid with a peptide bond. This process is called translocation. The process of Translation and translocation is continued until the ribosome attaches to a nonsense or stop codon. These codons signal for the ribosome to detach from the mRNA.