Environmental Effects and Epigenetics Flashcards Preview

Molecules to Man > Environmental Effects and Epigenetics > Flashcards

Flashcards in Environmental Effects and Epigenetics Deck (10):

What are housekeeping genes

Genes that code for common structural proteins/enzymes


What are specialised genes

Genes that code for proteins that differentiate cells


How is transcription initiated

Basal machinery factors unwind DNA
TATA box indicated start site
General transcription factors bind + start transcription + recruit RNA polymerase


How is the gene regulated

Transcription factors receive messages from inside/outside of cells eg. phosphate levels


What determines the rate of transcription

Multiple enhances upstream/downstream
Transcription activators


Describe the structure of chromatin

Chromosome = One centromere. 2 telomeres
Histone Protein = Pack DNA into repeating DNA-Pn Particles
Nucleosome = 8 Histones and associated DNA


What is the function of histone modification

Carry information
Regulatory information
Layer of information that overlays DNA sequence


What do nucleosome modifications do

Turn genes on/off
Respond to changes in internal/external environment


What happens in X inactivation

1 of 2 X inactivated during early development
Inactivated X packaged into chromatin, condensed and turned into stone
Affects dosage compensation


Women have same X gene products as men but men only have 1 X chromosome. Why?

Gene dosage compensation = equalises gene expression levels