Central Dogma of Molecular Biology

• Central Dogma of Molecular Biology


  Basic underlying principle in the field of genetics

  • process in which genetic information flows from DNA to RNA, to make functional product proteins.
• DNA


  Genetic material within the nucleus.
• Replication


  Creates new copies of DNA
• Transcription


  Creates an RNA using DNA information.
• Translation


  Creates a protein using RNA information
• Deoxyribonucleic Acid (DNA)


  Genetic material passed on from parents to offspring

  • Prokaryotes, found in nucleoid region in cytoplasm
  • Eukaryotes, found in nucleus and mitochondria.
• Structure of DNA

  Proposed by Biologist, Francis Crick and James Watson in 1953

  • Double Helix Structure - twist spirally
  • Nucleotide - Backbone or Building Block
  • Nucleotide is composed of phosphate group, sugar, and nitrogenous bases
• Genes


  The instructions for inherited traits
• Nitrogenous Bases

  Purines - Double ringed structure

  Pyrimidines - only one ring in their structure
• Nitrogenous Bases (structure)

  Adenine

  Thymine

  Cytosine

  Guanine

  and Phosphate Backbone

  
  

  Take Note: Uracil can only be found in RNA
• Purines (structure)


  Guanine

  Adenine
• Pyrimidines


  Cytosine

  Thymine

  Uracil
• Complementary Base Pairing

  Each pair should contain purines and pyrimidines

  • Each nucleotide is paired together by hydrogen bond.
  • Uracil replaces Thymine in RNA
• Ribonucleic Acid (RNA)


  Single Stranded that is composed of nucleotides

  • Sugar Backbone is ribose
  • DNA: Manual; RNA: "Photocopy"
  • Helps the cell get the instructions needed to produce proteins
• 3 types of RNA

  mRNA - located in Nucleus and Cytoplasm

  tRNA - Cytoplasm

  rRNA - Ribosome
• Messenger RNA (mRNA)


  Carries instructions for polypeptide synthesis from nucleus to ribosome in cytoplasm

  
  

  Made from DNA

  
  

  Transcribes the genetic code from DNA into a form that can be read and used to make proteins

  
  

  Nucleus to Cytoplasm
• Transfer RNA (tRNA)


  Carries amino acids to ribosomes and matches them with mRNA.

  
  

  Brings amino acids to ribosomes
• Ribosomal RNA (rRNA)


  Forms important part of both subunits of the ribosome

  
  

  Where proteins are made

  
  

  Converts amino acids to proteins
• Importance of RNA

  Acts as an enzymes

  • Certain RNA defects can result in human diseases