Table of Contents
Is DNA damage a mutation?
DNA damage is distinctly different from mutation, although both are types of error in DNA. DNA damage is an abnormal chemical structure in DNA, while a mutation is a change in the sequence of base pairs.
What is considered DNA damage?
DNA damage is a change in the basic structure of DNA that is not itself replicated when the DNA is replicated. A DNA damage can be a chemical addition or disruption to a base of DNA (creating an abnormal nucleotide or nucleotide fragment) or a break in one or both chains of the DNA strands.
What are sources of DNA damage mutation?
Endogenous sources of DNA damage include hydrolysis, oxidation, alkylation, and mismatch of DNA bases; sources for exogenous DNA damage include ionizing radiation (IR), ultraviolet (UV) radiation, and various chemicals agents.
How do mutation and DNA damage differ?
Although both DNA damage and DNA mutation are types of error in DNA, they are distinctly different from each other. DNA damages are physical abnormalities in DNA such as single- and double-strand breaks, while a mutation is a change in the base sequence of the DNA.
What are the different types of DNA repair?
At least five major DNA repair pathways—base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination (HR) and non-homologous end joining (NHEJ)—are active throughout different stages of the cell cycle, allowing the cells to repair the DNA damage.
How is damaged DNA repaired?
Most damage to DNA is repaired by removal of the damaged bases followed by resynthesis of the excised region. Some lesions in DNA, however, can be repaired by direct reversal of the damage, which may be a more efficient way of dealing with specific types of DNA damage that occur frequently.
What is DNA chain damage?
Single strand and double strand cleavage of the DNA may occur. Single strand breaks may result from damage to the deoxyribose moiety of the DNA deoxyribosylphosphate chain. Breaks also result as an intermediate step of the base excision repair pathway after the removal of deoxyribose phosphate by AP-endonuclease 1.
What are the 2 types of mutations?
Two major categories of mutations are germline mutations and somatic mutations. Germline mutations occur in gametes. These mutations are especially significant because they can be transmitted to offspring and every cell in the offspring will have the mutation. Somatic mutations occur in other cells of the body.
What are the four types of factors that cause DNA damage?
The four types of factors that cause DNA damage are: (1) Hydrolysis (2) Deamination (3) Alkylation and (4) Oxidation. Cause # 1. Hydrolysis: DNA consists of long strands of sugar molecules called deoxyribose that are linked together by phosphate groups.
What happens when the DNA repair system is damaged?
Unfortunately, when levels of endogenous DNA damage are high, which might occur as the result of an inactivating mutation in a DNA repair gene, or when we are exposed to harmful exogenous agents like radiation or dangerous chemicals, the cell’s DNA repair systems become overwhelmed.
What are the different types of DNA repair pathways?
At least five major DNA repair pathways—base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), homologous recombination (HR) and non-homologous end joining (NHEJ)—are active throughout different stages of the cell cycle, allowing the cells to repair the DNA damage.
How do cDNA cells respond to DNA damage?
Cells respond to DNA damage by instigating robust DNA damage response (DDR) pathways, which allow sufficient time for specified DNA repair pathways to physically remove the damage in a substrate-dependent manner.