Final answer:
DNA duplex melting is an endothermic phase transition where the double helix structure separates into single strands requiring heat. The TM varies with G=C content and UV spectroscopy is used to monitor this process.
Step-by-step explanation:
The thermodynamics of DNA duplexes melting is akin to a phase transition, where the double helix structure separates into two single strands. The process is endothermic, meaning it requires the absorption of heat. During DNA melting hydrogen bonds between bases are disrupted and hydrophobic interactions are overcome. The temperature at which the DNA is half-denatured is called the melting temperature or TM which varies depending on the guanine-cytosine (G=C) content of the DNA.
The higher the G=C content the higher the melting temperature. This kind of thermal transition can be monitored using UV spectroscopy and is important in studies involving DNA stability and characterization.