L14: The environment and epigenetics Flashcards
What is a gene
A sequence that codes for a protein
What is a gene composed of
- enhancers this is regulatory sequence
- promoter this is also a regulatory sequence
- structural sequence which codes for the protein
What does a enhancer do
Transcription factors bind to the enhancer which control the transcription rate and initiate polymerase 2 to the promote region
What does the promoter do
Transcriptional factors and DNA polymerase 2 bind to initiate transcription of the gene to create the protein. The transcriptional factors bound to the sequence recruit DNA polymerase 2 as they cannot recognise the sequence
How many enhancers are there on a gene
Many
How many promoters are there for one gene
One
How are the transcriptional factors bound to enhancer activates
By the environment
What is epigenetics about
It is about the chromosome
How is chromosome arranged
DNA>DNA double helix> chromatin wrapped around nucleosomes> chromosome
What is a nucleosome made of
8 histones
Are are the tails of the histone involved in epigenetics
Histone tails can become chemically modified which turns genes on.
How does chemical modification occur in histone tails
By enzymes
What are the enzymes called that control chemical modification in histone tails
- histone acetyl transferase
- histone de-acetlyases
What does the enzyme histone acetyl-transferase do to histone tails
Chemical modification to tails which turns genes on
What does the enzyme histone de-acetylase do to histone tails
Remove the chemical modification so genes are off
