Flashcards in 2.4 Control of gene expression Deck (64)
What is critical for all organisms?
Regulation of gene expression
What are three important things for the regulation of gene expression?
Genes and regulatory elements. Levels of gene regulation. DNA-Binding Proteins
What are operons?
In bacteria, groups of genes that are transcribed as a unit
What are structural genes?
Enconding proteins that are not regulatory
What are two examples of strucutural genes?
Tubulin and enzymes
What are regulatory genes?
Encoding products that interact with other sequences and affect the transcription and translation of these sequences
What is an example of regulatory genes?
What are regulatory elements?
DNA sequences that are not transcribed but play a role in regulating other nucleotide sequences.
What is an ex of regulatory elements?
What is constitutive expression?*
Genes is always on.
What is positive control?
Turn on gene expression
What is negative control?
Turn off gene expression
Where does transcription begin?
the initial transcription binding site, not the start codon
Why does the splicesome have to be nearly perfect?
Because the message will be trash if its not
What are domains?
group of AA responsible for binding to DNA forming hydrogen bonds with DNA
What is a motif?
Within the binding domain, simple structure that fits into the major groove of the DNA
What are three types of DNA binding proteins?
Helix-turn-helix, zinc fingers, leucine zipper
How are DNA-binding proteins grouped?
On structures or motifs
What is the structure of an operon?
What is a promoter?
region of DNA that initiated transcription of a particular gene
What helped produce the large phenotypic differences between humans and chimps?
Changes in small number of regulatory sequences
How do euk and bac differ pertaining to gene regulation? 3 ways
In euk: 1. Each structural gene has its own promoter and is transcribed separately. 2. DNA must unwind from the histone proteins before transcription. 3. Transcription and translation are separated in time and space.
What is the significance of DNase I hypersensitivity?
These sites have a more open chromatin configuration site. Include promoters, enhancers, insulators, silencers and locus control regions.
What are two ways for histone modification?
Addition of methyl groups to histone tails and addition of acetyl groups to histone proteins
What do chromatin remodeling complexes do?
reposition the nucleosomes, bind to DNA sites and unwind.
What happens when histone proteins are acetylated?
Their charge is altered, allowing transcription factors to bind to DNA. Activating genes.
Where does DNA methylation occur?
In the CpG islands.
whats the difference between active genes and unactive genes?
The Active genes will have the Cs unmethylated. The unactive genes will have the Cs methylated.
What is ChlP?
Tool used to study DNA binding proteins or events. By using antibodies that bind to specific proteins.