Why is the DNA Denaturation Transition First Order?
- Event time: 1:00pm
- Event date: 14th August 2000
- Speaker: David Mukamel (Department of Physics of Complex Systems Weizmann Institute of Science Israel)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Thermal denaturation or melting of double-stranded DNA is the process by which two strands unbind upon heating. The nature of the transition has been investigated for almost four decades. Experimentally the melting curve exhibits a multistep behaviour consisting of plateaus with sharp jumps. These jumps have been attributed to the unbinding of domains characterised by different frequencies of AT and GC pairs. Simple theoretical models studied for the last thirty years predict the transition to be continuous in two and three dimensions. In our work we consider analytically the effects of excluded volume interaction between unbound loops and the rest of the chain. The phase transition is now found to be first order in dimensions two and above.
This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..