Explain the stages of protein synthesis

Transcription - occurs in the nucleus. 

to prevent damage to the DNA, when a protein is required to be synthesised, a copy of that particular gene is encoded onto an mRNA (messenger RNA) molecule.The DNA Double Helix is untwisted and the antiparallel strands are unzipped - the Hydrogen bonds between the bases are broken and exposes the bases. (helicase enzyme)the DNA molecule 'opens up', exposing the gene to be read. Free RNA nucleotides, which are complementary using the base paring rules C-G and A-U bond to the exposed bases on the template Strand.                        The RNA backbone then forms creating an mRNA (messenger RNA) molecule which is identical to the Coding Stand (opposite to the Template Strand). The mRNA then peels away from the DNA strand.

The molecule then leaves the nucleus through a Nuclear Pore.

Translation - occurs on the ribosomes in the rough endoplasmic reticulum

1. The mRNA molecule travels to and attaches to a Ribosome located on the Rough Endoplasmic Reticulum, or in the Cytoplasm.

2. the sequence of Amino Acids is read and the instructions are Translated to a Polypeptide Chain.

3. tRNA (Transfer RNA) carries amino acids. When the tRNA carrying the correct amino acid in the sequence collides with the Ribosome, the amino acid joins with the previous amino acid, forming a Peptide Bond.

4. This produces a polypeptide chain, whose Primary Structure is dictated by the sequence of bases in the gene. Primary Structure gives rise to Secondary and Tertiary Structures.