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In biochemistry, denaturation is a process in which proteins or nucleic acids lose folded structure present in their native state due to various factors, including application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation and radiation, or heat. [3]
The most famous example is the hyperchromicity of DNA that occurs when the DNA duplex is denatured. [1] The UV absorption is increased when the two single DNA strands are being separated, either by heat or by addition of denaturant or by increasing the pH level. The opposite, a decrease of absorbance is called hypochromicity.
The process of DNA denaturation can be used to analyze some aspects of DNA. Because cytosine / guanine base-pairing is generally stronger than adenine / thymine base-pairing, the amount of cytosine and guanine in a genome is called its GC-content and can be estimated by measuring the temperature at which the genomic DNA melts. [ 2 ]
In the earliest forms of denaturation mapping, DNA was denatured by heating in presence of formaldehyde [1] or glyoxal [3] and visualized using electron microscopy. Dyes that selectively bind to double stranded DNA like ethidium bromide could be used to monitor the extent of denaturation. But it was not possible to observe locations of ...
The polymerase chain reaction is the most widely used method for in vitro DNA amplification for purposes of molecular biology and biomedical research. [1] This process involves the separation of the double-stranded DNA in high heat into single strands (the denaturation step, typically achieved at 95–97 °C), annealing of the primers to the single stranded DNA (the annealing step) and copying ...
DNA damage inhibits M-CDKs which are a key component of progression into mitosis. In all eukaryotic cells, ATR and ATM are protein kinases that detect DNA damage. They bind to DNA damaged sites and activate Chk1, Chk2, and, in animal cells, p53. Together, these proteins make up the DNA damage response system.
A hot water solution containing 73.1% (mass) of NaOH is a eutectic that solidifies at about 62.63 °C as an intimate mix of anhydrous and monohydrate crystals. [ 21 ] [ 20 ] A second stable eutectic composition is 45.4% (mass) of NaOH, that solidifies at about 4.9 °C into a mixture of crystals of the dihydrate and of the 3.5-hydrate.
These reactive chemical species can reach DNA by diffusion and the bimolecular reaction damages the DNA (oxidative stress). Unlike direct DNA damage which causes sunburn, indirect DNA damage does not result in any warning signal or pain in the human body. The bimolecular reactions that cause the indirect DNA damage are illustrated in the figure: