Module 35 Flashcards
Regulation of Gene Expressions (83 cards)
What happens when a gene is expressed
The doing of the Central Dogma
A functional product is produced, such as a protein
What is gene regulation
Gene expression does not happen at all times under all conditions
It is the when, where, and how much of gene expression
What allows for cell specialization and for multicellular organisms to develop
Gene regulation
Where
In which cells
When
Under what conditions, environmental conditions, or period of life (development)
Specialization
Different types of cells express different genes
Most cells share the same sets of genes, but different sets of them are expressed
Do skin cells have the genes that encode for isulin
YES, but they are not expressed in these cells
When is insulin expressed in the pancreas
When it receives a signals that the body’s blood sugar levels are high
How does gene regulation help save energy and resources
By not activating all genes at all time
When does gene regulation occur
Anytime during DNA replication
Level of chromosome to even after the protein is made
What are some additional levels of gene regulation that are not possible in eukaryotes
How DNA is packaged into chromosomes, RNA processing, and the separation between transcription and translation,
At what level is gene regulation done in prokaryotes
In the level of transcription
What does gene expression involve in prokaryotes
Transcription of the gene into mRNA and translation of the mRNA into protein
POSITIVE REGULATORY MOLECULE
Binds to DNA at a site near the gene in order for transcription to take place
-usually a protein
-ACTIVATOR
NEGATIVE REGULATORY MOLECULE
binds to the DNA at a site near the gene and prevents transcription
-usually a protein
-REPRESSOR
Activators
Required for RNA polymerase to bind to the DNA strand and turn on the transcription
A Positive regulatory proteins
What two binding sites can DNA have
(both eukaryotes and prokaryotes)
One for the activator and one for the polymerase
What is RNA polymerase called when it attaches to the binding site after the activator
It is the PROMOTER
An Allosteric Effect
When a molecule binds to a protein, changing its shape alters its activity.
What can the allosteric effect cause when an activator is effected
It can result in more transcription of the gene.
Small molecules bind to and change the activity of the activator
How does RNA polymerase bind during negative regulation
RNA polymerase binds on its own to the DNA molecule, allowing transcription to occur.
The negative regulatory protein can bind and turn off transcription
Activator
Required to turn on transcription
A positive regulatory molecule
Promoter
RNA polymerase
Activates the RNA transcription
Repressor
Part of the negative regulatory process
Turns off DNA transcription