In: Biology
4. Imagine a gene promoter is located in “closed” chromatin – meaning the gene can’t be expressed – and you wish to turn on gene expression. Describe 3 changes you can make to the DNA (or proteins that interact with DNA) to turn on gene expression. (There may be more than 3 correct answers but you only need to give three.)
5. Imagine the opposite scenario to #4: a gene is currently actively expressed and you wish to turn OFF gene expression. What changes can you make to turn off this gene?
4) chromitin remoduling occur to make DNA from inactive to active by :-
A) Demethylation- Removal of methyl group from histone protein cause removal of histone protein
B) Acetylation of histone protein- addition of acetyl group to histone protein introduced negative charge and hence this leads to negative charge replusion of acetyl group with phosphate group that leads to release of histone protein from DNA
C) Addition of phosphate group to hostone also cause the effect as discussed in B point and cause release of histone protein from DNA and transcription take place on surgqce of DNA
5) to switch off the gene, following stratagoes could be used-
A) Methylation of DNA- methylation cause inactivation of gene and transcription will be switch off
B) Deacetylation of histone protein by enzyme deacteylase which cause removal of acetyl group from histone protein and hence histone reassociate with DNA and make gene inactive
C) Dephosphorylation:- which leads to removal of phosphate group histone protein and hence histone protein reassociated with DNA and make it inactive.
Hope it's clear..thanks