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The Lac Operon definitions Flashcards

The Lac Operon definitions
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  • Lac Operon
    An inducible operon in E. coli that is repressed in the absence of lactose and activated in its presence to metabolize lactose.
  • Inducible Operon
    An operon that is typically off but can be activated by an inducer molecule, allowing gene expression in response to specific environmental conditions.
  • Repressible Operon
    A gene system that is typically active but can be inhibited when a specific molecule binds to a repressor, preventing transcription.
  • Lactose
    A disaccharide sugar composed of glucose and galactose, metabolized by certain bacteria via the lac operon, which is activated in its presence.
  • Genes
    Segments of DNA that encode instructions for synthesizing proteins or functional RNA molecules, influencing an organism's traits and biological functions.
  • Lac Z
    A gene in the lac operon encoding -galactosidase, an enzyme that hydrolyzes lactose into glucose and galactose.
  • Lac Y
    Lac Y encodes a permease that facilitates the transport of lactose into the bacterial cell, enabling its metabolism when lactose is present.
  • Lac A
    Encodes thiogalactoside transacetylase, an enzyme involved in lactose metabolism within the lac operon, though its exact role in lactose utilization is less understood compared to LacZ and LacY.
  • Repressor Protein
    A protein that binds to the operator region of an operon, blocking RNA polymerase and preventing transcription of specific genes, typically in the absence of an inducer.
  • Lac I
    A protein that binds to the operator of the lac operon, inhibiting transcription in the absence of lactose.
  • Operator
    A DNA segment in an operon where a repressor protein binds to inhibit transcription of adjacent genes.
  • RNA Polymerase
    An enzyme that synthesizes RNA from a DNA template during transcription, essential for gene expression.
  • Transcription
    The process where RNA polymerase synthesizes RNA from a DNA template, producing mRNA for protein synthesis.
  • Promoter
    A DNA sequence where RNA polymerase binds to initiate transcription of a gene.
  • E. Coli
    A common gut bacterium that utilizes the lac operon to metabolize lactose, becoming active in its presence and repressed in its absence.
  • Inducer Molecule
    A molecule that binds to a repressor protein, preventing it from binding to the operator, thus allowing gene transcription in an inducible operon.
  • Metabolism
    The set of chemical reactions in a cell that convert nutrients into energy and building blocks for growth, while also eliminating waste products.