Epigenectics Flashcards
What is epigenetics?
The study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself.
What is the epigenome?
a multitude of chemical compounds that can tell the genome what to do.
What is a histone?
A protein that DNA is wrapped around inside a chromosome.
What condition are Oncogenes associated with?
Cancer
Describe how histone modification can affect the transcription of the genes that the histones are associated with.
Histone modification can affect how condensed the chromatid associated with the histones is/ how accessible the DNA is. This affects whether the proteins/enzymes needed for transcription are able to bind to the DNA and transcribe the gene
What do oncogenes have the potential to cause?
Cancer
Are oncogenes expressed at a high or low rate in cancer cells?
They are expressed at high levels
What do oncogenes code for?
oncogenes code for the proteins that stimulate the transition from one stage in the cell cycle to the next.
What does methylation of these genes cause?
methylation, in these genes can lead to the cell cycle being continually active. This may cause excessive cell division resulting in a tumour.
What is p53?
P53 is a tumour suppressor protein produced from an oncogene.
What do p53 proteins stop happening?
stops the cell cycle by inhibiting enzymes between the G1 and S phases, preventing the cell copying its DNA.
Why would a lack of p53 cause cancer cells to develop?
a lack of p53 means the cell cannot stop entry into the S phase. Therefore, these cells have lost the control of the cell cycle.
What cancers is p53 linked to?
Loss of tumour suppressor protein p53 has been linked to skin, colon, bladder and breast cancers.
