Central dogma and gene regulation

• Central dogma


  The flow of genetic information from DNA to RNA to protein

  
• Gene regulation

  The control of gene expression
• Gametes

  Haploid reproductive cells (sperm and egg)
• Zygote

  The cell formed by the union of a sperm and an egg
• Meiosis

  The process of cell division that produces gametes
• Fertilization

  The union of a sperm and an egg to form a zygote
• Haploid/germ cells


  Cells with one set of chromosomes
• Diploid/Somatic cells


  Cells with two sets of chromosomes
• There are approximately 200 different cell types in the human body
• There are approximately 10^14 cells in the human body
• Mitosis

  The process of cell division that produces two genetically identical daughter cells
• The human genome consists of 46 chromosomes
• Chromosomes

  Packages of DNA
• Chromosomes

  • Composed of DNA: genetic material
  • Composed of proteins: provide an organized structure

  
• Chromatin


  The complex of DNA and proteins that makes up chromosomes

  
• Chromatin is too thin to be seen under a light microscope, but can be seen when it condenses during cell division
• Homologous chromosomes

  • Similar in size, centromere location, and genes
  • Sex chromosomes: X or Y (not homologous)
  • Autosomes: remaining 22 pairs
• The human genome is approximately 2 meters long, but is packaged into 46 chromosomes
• DNA strand

  Has a 3' end with a hydroxyl group and a 5' end with a phosphate group, with the 5' carbon of one nucleotide attached to the 3' carbon of the next by a phosphodiester bond

  
• DNA strands grow at the 3' end, but not at the 5' end
• DNA molecules are read in the 5' to 3' direction

  
• DNA replication


  The process of making an exact copy of the long linear chromosomes

  
• DNA replication

  • Must occur very quickly (multiple replication origins, bidirectionally)
  • Must occur very accurately
  • Must occur at the appropriate time in the cell cycle
• Central dogma


  The flow of genetic information from DNA to RNA to protein

  
• Gene regulation

  The control of gene expression
• Gametes


  Haploid reproductive cells (sperm and egg)
• Zygote

  The cell formed by the union of a sperm and an egg
• Meiosis

  The process of cell division that produces gametes
• Fertilization

  The union of a sperm and an egg to form a zygote
• Haploid/germ cells


  Cells with one set of chromosomes
• Diploid/Somatic cells


  Cells with two sets of chromosomes
• There are approximately 200 different cell types in the human body
• There are approximately 10^14 cells in the human body
• Mitosis

  The process of cell division that produces two genetically identical daughter cells
• The human genome consists of 46 chromosomes
• Chromosomes

  Packages of DNA

  
• Chromosomes

  • Composed of DNA: genetic material
  • Composed of proteins: provide an organized structure

  
• Chromatin


  The complex of DNA and proteins that makes up chromosomes

  
• Chromatin is too thin to be seen under a light microscope, but can be seen when it condenses during cell division
• The human genome is approximately 2 meters long, but is packaged into 46 chromosomes