acetylation or methylation Flashcards
what is acetylation
when an acetyl group is transferred to a molecule from the acetyl coenzyme a
what is deacetylation
when an acetyl group is removed fro ma molecule
what does decreased acetylation do
increases the positive charges on histones and increase the attraction to the phosphates of the dna creating a condensed dan histone complex
what happens to the association and so what
the dna and histone are more condensed which means it is less accessible to transcription factors so mrna cannot be produced and gene is switched off
what is methylation
addition of a methyl group to the cytosine base
what does methylation normally do
prevent the binding og transcriptional factors to the dna
attaching proteins that condense dna histone complex by inducing deacetylation which makes the DNA inaccessible to transcription factors
what has rats experiemtns shown
female offsprings who received good care when young respong better to stress in later lifes and nurture their offsprings better
what does good maternal behaviour do
transmit epigenetic information into their offsprings dna without passing through an egg or a sperm
what happens in humans when mother has gasteronial diabetes
the featus is exposed to high concentration of glucose and cause epigenetic changes in the daughters dna increasing daughters chance of developing diabetes too
what does the sperm and egg do
search the genome and erase the epigenetic tages in order to return the cell to a clean slate
however what happens
some chemical tags escape this clearing and gets passed on to the offsprings
what can altering the epigenetic process do
cause abnormal activation or silencing of genes and are associated with diseases
what did researcher find in diseased colonal cancer tissue
it had less dna methylation than normal which inhibits transcrioption
what does this mean for the activity
activity of the gene will be higher than normal
although epigenetic changes doesn’t change dna bases what can it lead to
an increase in mutations
