a process in which various enzymes together repair mutational damage to DNA
The process through which mutations in DNA are repaired. The basic DNA repair mechanism involves nucleases that cut out the damaged area of DNA, polymerases that fill in the gap with the correct nucleotides, and ligases that seal the nick between the new segment of DNA and the original DNA strand.
There are many ways in which DNA can be damaged. For example, chemicals can cause changes in the DNA sequence, or mistakes can be made during the copying of DNA that happens just before a cell divides to produce two new cells. Every cell has a set of proteins whose role is to repair damaged DNA. If the genes that produce these repair proteins are themselves damaged by mutation, the cell may be unable to repair damaged DNA effectively.
The reconstruction of a continuous two- stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post- replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post- replication repair are sometimes referred to as "dark repair" because they do not require light. [MeSH, 1974
The DNA in the nucleus of a cell is constantly being damaged. To prevent cancer occurring, cells have a number of sophisticated mechanisms to repair this damage. There are at least 130 genes involved in repairing a cell's DNA. If any of the DNA repair genes themselves become damaged, a cell is more likely to become cancerous, as it cannot repair future damage as efficiently.
the process of correcting the genetic mistakes that are made each time a cell divides. If the repair process does not go right, it can increase the chances of a person having some forms of cancer.
DNA damaged through a variety of mechanisms can be removed and repaired by a complex set of processes.
DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light can cause DNA damage, resulting in as many as 1 million individual molecular lesions per cell per day.Lodish H, Berk A, Matsudaira P, Kaiser CA, Krieger M, Scott MP, Zipursky SL, Darnell J. (2004). Molecular Biology of the Cell, p963.