DNA repair and replication are closely linked. They both work together to keep our genetic material safe and healthy. When our cells copy DNA, they make some mistakes. On average, there could be one mistake for every 100,000 pieces of DNA. Luckily, special proteins called high-fidelity DNA polymerases help fix these mistakes very accurately. But even with their help, mistakes and damage can still happen. That’s why we have DNA repair systems in place.

How DNA Repair Works:

1. Mismatch Repair (MMR):

   • MMR deals with mistakes that are missed during DNA copying. It finds and corrects places where the DNA bases don’t match up correctly, which helps prevent mutations. Research shows that MMR can decrease the mistakes by up to 100 times.

2. Base Excision Repair (BER):

   • BER kicks in when there are damaged parts in the DNA. Each day, our cells can have about 18,000 changes to a specific base called cytosine. BER helps remove these damaged bases so that DNA copying can keep going smoothly.

3. Nucleotide Excision Repair (NER):

   • NER is important for fixing larger problems, like extra pieces stuck to the DNA that could slow down the copying process. NER can remove thousands of these issues every day, helping the DNA copying process to keep moving forward.

What Happens If Repair Fails:

If these repair systems don’t work properly, the number of mistakes in DNA can increase. Studies suggest that about 60% of cancers have issues with one or more DNA repair pathways. This shows just how important the connection between DNA copying and repair really is.