Control of Gene Expression Flashcards
_____________ is the result of cells expressing different genes
Cell Differentiation
Cells have the ability to change which genes they express without altering the ___________ of their DNA
Nucleotide sequence
Gene expression can be regulate at __________ from DNA to RNA to proteins
Various Steps
What are the ways cells can control the amount of protein it contains ?
- Controlling when & how often a gene is transcribed
- Controlling how an RNA transcript is spliced or processed
- Selecting which mRNA are exported from the nucleus to the cytosol
- Regullating how quickly cetain mRNA molecules are degraded
- Selecting which mRNAs are transcribed into protiens by ribosomes
- Regulating how rapidly specific proteins are destroyed after they have been made
Transcription regulators (Transcription factors)
Proteins that bind to specific DNA sequences & control gene transcription
Different cells contain all the __________ needed to direct the formation of a complete organism
Nucleotide sequence (Genetic Information)
There is a _________ of cells because the genes are expressed differently
Varitey
Cells are cable of altering their patterns of _________ in response to outside signals
Gene Expression
The promoter of both bacterial & eukaryotic genes include __________
Transcription Site
Transcription Site
Is where RNA is syntheized & where the assembly of other sequences that contain recognition site for proteins (like the sigma factor or like the transcription factors)
Genes also have _________
Regulatory DNA sequences
Regulatory DNA sequences
Used to switch the gene on or off
Regulatory DNA sequence have to be recognized by __________ to be able to swtich a gene on or off
Transcription regulators
The binding of a __________ to a regulatory DNA sequences that acts as the switch to control transcription
Transcription Regulator
____________ bind to the DNA helix as a dimers which cause the strength in protein - DNA interaction to increase
Transcription regulators ( type of proteins)
__________ switches allows cells to respond to changes in their environment
Transcription
When a ____________ binds to an operator it blocks access of the RNA polymerase to the promoter which prevents transcription from occuring & even the prodcution of proteins
Transcription regulators
__________ turn genes off
Repressors
__________ turn genes on
Activators
Transcriptional respessor (type of protein)
Switches genes off (represses them)