Card Set Information

2011-12-16 23:39:43

Show Answers:

  1. Operon
    • Set of structural genes with related functions that share a common promoter
    • Genes are controlled by shared promoter
    • Genes are transcribed together and produce a single mRNA
  2. Regulator gene
    • Binds the operator in the operon of the structural genes
    • Has its own promoter
    • Encodes a protein that regulates transcription not considered an actual part of the operon, but it affects the operon function
  3. Structural genes
    • Encode proteins that are used in metabolism or biosynthesis
    • Also includes those that encode proteins that play a structural role in the cell
  4. Regulatory genes
    • Genes whose products interact with other sequences and affect the transcription or translation of those sequences
    • Products: RNA or proteins
  5. DNA binding proteins
    • Part of regulatory genes
    • Specialized proteins that bind to DNA sequences and affect their expression
    • They have special motifs that facilitate binding to and altering DNA
  6. lac operon
    • An operon required for the transport and metabolism of lactose in E. coli
    • Consists of three structural genes: lacZ, lacY, lacA(i)
  7. Structure of the lac operon
    • The lac operon consists of three structural genes, a promoter, a terminator, regulator, and an operator
    • Transcription of all genes starts with the binding of the enzyme RNA polymerase, a DNA binding protein, which binds to a specific DNA binding site, the promoter, upstream of the genes
  8. Regulatory elements
    • Sequences that are not transcribed but affect expression of sequences to which they are linked
    • Not actually a gene
  9. Absence of lactose
    The repressor protein encoded binds to the lac operator and prevents transcription