Question

There is a positive correlation between GC content and melting temperature. Does this imply that organisms with DNA that has low GC content can not survive in extreme temperatures? please list references to support your answer 30 marks(Please answer in essay form)

Answer 1

Solution

The GC content of DNA, mRNA and its secondory structure are important for determination of melting temperature of DNA.Guanine and Cytosine is always bind with each other by triple hydrogen bond while Adenine and Thymine bind with each other by double hydrogen bond.so GC triple hydrogen bond is stronger and requires more energy/temperature for its melting/DNA strands.The GC content of mRNA plays an important role in translational inhibition.so if GC content is decreased then there will no formation of secondory structure within mRNA and no translational inhibition occure.The GC content of thermophilic bacteria is about 70 % compared to other mesophilic bacteria.

stability of mRNA is important for functioning of cell.cell having high GC content which will withstand for higher temerature.because melting and GC content are directly correlated with each other in some microbs to live and adapt for higher temperature.so there is no chance to survive at high temperature.because it desturbs and destabilize the secondory structure of DNA and mRNA as well as tRNA and rRNA required for various functions of cells.

Therefore as there of correlation between GC content and melting tempearature so It is imply that organisms with DNA that has low GC content can not survive in extreme. temperatures.

References

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2951671/

  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3024870/