Ch.13 Gene Regulation
Polycistronic mRNA
An mRNA that encodes more than one protein.
Constitutive Genes
An unregulated gene that has constant levels of expression in all conditions over time.
Activators
Bind to the DNA and increase the rate of transcription.
Structural Genes
Code for proteins.
Regulatory Gene
Codes for transcription factors that regulate transcription of the operon.
Lac Operon
Contains the genes for proteins that allow it to metabolize lactose.
Regulatory Transcription Factors
Proteins that bind to DNA in the vicinity of a promoter and affect the rate of transcription of one or more nearby genes.
Promoter Region
For mRNA polymerse recognition.
Proteomes
The collection of proteins they make - are quite different; this is due to gene regulation.
Cis acting element
a DNA segment that must be adjacent to the gene that it regulates. ex. The lac operon
Trans- effect
a form of gene regulation that can occur even though two DNA segments are not physically adjacent .
Gene Expression
Is the process by which the information within the gene is made into a functional product, such as a protein or RNA molecule.
Genome
Meaning they carry the same set of genes .
Gene Regulation
Refers to the ability of cells to control the expression of their genes.
Cell Differentation
The process by which cells become specialized into particular types.
Operator
The regulatory switch (on or off) that the transcription factor will bind to.
Represors
Transcription factors that bind to DNA , and inhibit transcription .
inducer
a small effector molecule that increases the rate of transcription.
Operons
are cluster of genes that code for proteins that are used for common function . They consist of a regulatory gene, a promoter gene, an operator gene, and the structural gene.
Hemoglobin protein
is composed of four globin polypeptides, two incoded by one globin gene and two encoded by another globin gene.