The central dogma of molecular biology explains the flow of genetic information within a cell

• DNA is the master set of instructions for all cell activities (i.e. the genetic ‘blueprint’ of the cell)
  

• RNA (messenger RNA) is a temporary ‘photocopy' of specific genetic instruction (gene)
  

• Proteins are the products created from these instructions that carry out the cellular functions
  

DNA → RNA

The genetic instructions of a cell are stored within the sequences of double-stranded DNA molecules

• Double stranded molecules are more stable and help to ensure the conservation of the base sequence
  

• In eukaryotic cells, the DNA is stored within a membrane-bound nucleus – providing a further level of protection for the master sequence
  

When a genetic instruction needs to be expressed, a single-stranded RNA copy of that particular sequence is made (via transcription)

• The RNA molecule is a temporary copy that is complementary to the sequence on the template strand of DNA
  

• Once synthesised, the RNA will interact with ribosomes in the cytoplasm, which are responsible for synthesising proteins according to the genetic instructions