Life on Earth

Chapter 11
Gene Expression and Regulation
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The Relationship between Genes and Proteins
  • Most genes encode the information for the synthesis of a protein.
  • The sequence of bases in DNA codes for the sequence of amino acids in proteins.

    Synthesizing Proteins from the Instructions in DNA
  • Genetic information flows in a cell from DNA to RNA to protein.

    The Genetic Code
  • The genetic code uses three bases to specify each amino acid.

    RNA: Intermediary in Protein Synthesis
  • Transcription produces RNA molecules that are complementary copies of one strand of DNA.
  • Three types of RNA cooperate in protein synthesis.

    Protein Synthesis

    Mutations in DNA and Their Effects
  • Point mutations are changes in a single base.
  • Insertion and deletion mutations result from addition or removal of nucleotides.
  • Mutations differ in their effects on protein structure and function.
  • Mutations provide the raw material for evolution.

    Gene Regulation
  • Gene regulation in prokaryotes.
  • Gene regulation in eukaryotes.
  • Eukaryotic genes consist of DNA segments that code for the amino acid sequence of proteins interrupted by noncoding DNA segments.
  • Eukaryotic cells may regulate the transcription of individual genes, large parts of chromosomes, or entire chromosomes.



  • PH Sower © 1997 by Prentice-Hall, Inc.
    Simon & Schuster/A Viacom Company
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