Does circular ds dna respond 2 hyperchromism and hypochromism?how can any1 plz give the mechanism?
Hyperchromism happens when base-pairing in DNA is disrupted (denatured), e.g. by heating it. When ds linear DNA is denatured, the two strands can come completely apart and drift away from each other. With ds circular DNA, the strands can’t physically separate because of the way they’re wound around each other. But they can still go from being base-paired to being non-base-paired, which will result in hyperchromism. Note that in practice, heating up circular DNA will frequently cause at least one strand to break (for a variety of reasons). Then the two strands will be able to physically separate. However, that isn’t necessary to observe the hyperchromism. Even single-stranded DNA or RNA can show some hyperchromism as they’re heated. This happens for (at least) two reasons. One is that different parts of the same piece of DNA sometimes pair up over short regions, forming so-called hairpin loops. Heating denatures these paired regions, causing hyperchromism. The other thing is that even w
