Control of Gene Expression in Bacteria Flashcards
Gene Expression
Multistep process of converting information that is archive in DNA into molecules that actually do things in the cell.
Transcriptional Control
Regulation of gene expression by various mechanisms that change the rate at which genes are transcribed to produce mRNA.
NEGATIVE: binding of regulatory protein to DNA represses transcription.
POSITIVE: promotes transcription.
Translational Control
Regulation of gene expression by various mechanisms that alter the life span of mRNA or the efficiency or translation.
Post-Translational Control
Regulation of gene expression by modifications of proteins after translation.
Consitutively
Transcribe all the time.
Inducer
A small molecule that triggers transcription of a specific gene.
Mutagens
Chemicals that damage DNA and increase mutation rates.
Constitutive Mutants
Cells that are abnormal because they produce a product at all times.
Negative Control
Occurs when the regulatory protein (repressor) binds to DNA and shuts down transcription.
Positive Control
Regulator protein (activator) binds to DNA and triggers transcription. i.e. Catabolic Activator Protein (CAP) bound to cAMP in order to bind to DNA.
Operon
A region of bacterial DNA that codes for a series of functionally related genes and is transcribed from a single promoter into ONE mRNA.
Cotranscription
Genes are adjacent and are transcribed into one mRNA initiated from the single promoter. Results in 3 genes.
Allosteric Regulation
Regulation of an enzyme’s activity by binding of a regulatory molecule at a site that is distinct from the active site. Results in a change in the protein’s shape that affects the function of the active site.
Regulon
A set of separate genes or operons that contain the same regulatory sequences and that are controlled by a single type of regulatory protein.
Law of Segregation
2 alleles on of the parent cell segregate during meiosis , gametes contain one allele.
