Epigenetics And Gene Expression Flashcards
What is the definition of Epigenetics?
How is it caused?
Epigenetics is the heritable changes in gene function without changing the DNA base sequence
These changes are caused by Changes in the environment and can inhibit transcription.
What factors result in Epigenetics?
Factors such as Diet,stress and Toxins can add or remove Epigenetics to the DNA or histones
What is an Epigenome?
An epigenome is a single layer of chemical tags on DNA
How does a Epigenome control gene expression?
Epigenome impacts the shape of the DNA-histones complex whether the DNA is tightly wound so wont be expressed or unwound so it will be expressed.
Where does Methylation take place?
Methylation takes place on the DNA
Where does Acetylation take place?
Acetylation take place on Histones proteins.
What occurs in Methylation of DNA?
Increased Methylation of DNA inhibits transcription.
When Methyl groups added to DNA it attach to cytosine base prevents transcriptional factors from binding.
What occurs in Acetylation of Histones proteins?
If Acetyl Groups removed from DNA. Histones become more positive and are attracted more to the Phosphate groups on DNA
Resulting in DNA and Histones more Strongly associated.
So what combination of Methylation and Acetylation inhibits and allows transcription?
Increased Methylation and Decreased Acetylation both inhibit transcription.
Decreased Methylation and Increased Acetylation transcription will occur.
What are Tumour suppressor Genes?
Tumour suppressor genes are genes that produce proteins to slow down cell division and to cause cell death if DNA copying errors occur
What type of cancer can a mutation occurring in tumour suppressor gene?
Breast cancer.
