Gene Regulation Flashcards
(58 cards)
Gene expression
Cellular function
Which cell to be expressed?
- necessary proteins must be synthesised at the proper time and place
- all cells must regulate the synthesis of proteins from their DNA
- Turn on a gene = gene expression
- The regulation of gene expression conserves energy and space
turn on genes when required
more efficent
Turn on a gene
gene expression
Process or gene expression
1) take DNA from nucleus
2) double helix
3) unwind double helix - DNA polymerase
4) give RNA»_space; protein
What to consider - importance
- What cell?
- Which chromosomes?
- What part of DNA?
- What protein?
- How much protein?
- For how long?
- Where’s it going?
Everything starts with a _____ in cell biology.
SIGNAL
Cytoplasm: the process of DNA to degrated protein:
- Chromatin
- DNA
- RNA
- mRNA in nucleus
- mRNA in nucleus
6.mRNA in cytoplasm - Polypeptide (degradation of mRNA)
- Active protein
- Degradated protein
Define Epigenetics
process of turning genes off or on
Scilencing / supresing gene
gene NOT in action
Activation of gene
gene is turned on
histones
4 stacks of 2 - DNA tightly round the histones
all histones come together to form chromosomes
Gene cannot be expressed
Histone is bound too tightly to be READ by DNA polymerase
Unwind the gene
in results of +ive/-ive charges
enough unwinding for DNA polymerase to read to gene
Acetyl group bound to histone
Decrease attraction - DNA unwinds
ACETYLATION : When DNA unwinds
Open access - gene expression
DE-ACETYLATION : DNA tightly wound
Repression - DNA is locked tight
CANNOT be read
NO ACCESS to gene expression
Histone METHYLATION
The addition of a methyl group to a DNA strand
Low attraction unwind
Gene expression therefore DNA polymerase can get in to read codon
(can have) More than 1 methyl group
HYPERMETHYLATED (e.g 3 methyl groups on one histone)
Hypermethylated - traffic jammed
Cannot be read - no expression
More than 2 methyl groups:
CANNOT be expressed because there is no room for DNA polymerase to read it
Factors that effects epigenetics
DIET
Gene regulation - 3 stages
1) Transcriptional
2) Post-transcriptional
3) Translational
