Epigenetics Flashcards
What is epigenetics?
a heritable change in gene function that does not change the DNA sequence
What are these changes caused by?
environmental factors that can inhibit transcription
What are some factors that can add chemical tags to DNA?
diet, stress, toxins
What is meant by the term ‘epigenome’?
a single layer of chemical tags on the DNA
What does the epigenome impact?
the shape of the DNA histone complex and whether the DNA is tightly wound or unwound
What are unwound parts of DNA called?
chromatin
What DNA can be transcribed and translated?
parts that are exposed so chromatin
Why is DNA not transcribed in heterochromatin?
As transcription factors cannot bind
What is tightly coiled DNA called?
heterochromatin
What is methylation?
adding on a methyl group
Where do methyl groups attach to DNA?
on the Cytosine base
What does increased methylation result in?
inhibition of transcription
why does increased methylation reduce transcription?
tightly coiled means no transcriptional factors can bind so transcription cannot occur
Why does methylation result in heterochromatin?
methyl groups are positively charged, DNA is negatively charged so they attract and tightly coil
What is acetylation?
the addition of acetyl groups to the HISTONES
