- Proteins are made of long chains of amino acids joined by peptide bonds. There are 20 different amino acids
Structure of AA
- Proteins are important to a living cell as enzymes
- The purpose of DNA and mRNA is to provide a way for the cell to make proteins that have a set structure and to make proteins in the same way repeatedly
- When part of the DNA molecule,gene, takes part in making protein, the gene is said to be expressed. Expression of different genes produces a different protein eg gene A makes protein A when expressed, gene B produces protein B.
- Gene expression involves two processes - transcription of DNA into mRNA, followed by translation of mRNA code that ensures amino acids are placed in the correct order to form a protein.
Diagram of DNA becoming mRNA to protein