Central Dogma of Molecular Biology

• Illustrates the flow of genetic information in a biological system, from DNA to RNA to proteins.

  Central dogma of molecular biology
• three basic processes of central dogma of molecular biology

  • replication
  • transcription
  • translation
• DNA synthesis

  replication
• RNA synthesis


  transcription
• protein synthesis


  translation
• characteristics of replication

  1. semi conservative
  2. requires a primer
  3. synthesis proceeds in 5' to 3' direction
  4. bidirectional
  5. semi discontinuous
• also called as OKAZAKI fragments


  lagging strand
• two types of semi discontinuous

  1. leading strand
  2. lagging strand
• what enzyme unwinds the DNA by breaking the hydrogen bonds between nucleotides?

  helicase
• what enzyme relaxes the twisting tension during the unwinding process?

  girase
• what enzyme adds nucleotides complimentary to the DNA template?

  DNA polymerase III
• What enzyme proofreads the DNA molecules and removes primers to replace them with DNA nucleotides?

  DNA polymerase I
• What enzyme seals the gaps between DNA segments?

  Ligase
• The protein sigma factor searches a promoter sequence in the DNA
• the enzyme RNA polymerase attaches to promoter sequence and begins transcription
• RNA polymerase starts the elongation by adding RNA nucleotides
• the RNA polymerase moves along one of the DNA strands called what?

  anticoding strand
• the protein RHO factors binds to the RNA polymerase and disassociates it from the DNA
• Transcription produces three types of RNA

  1. messenger RNA
  2. transfer RNA
  3. ribosomal RNA
• helps form the structure of the protein making ribosome

  rRNA
• Carries information found in DNA

  mRNA
• transports amino acids to the ribosomes

  tRNA
• the molecular basis of phenotype lies in what?

  proteins
• transfer of the RNA into a protein

  translation
• synthesis of RNA from a DNA template

  transcription
• each amino acid is attached to its tRNA with the help of what enzyme?

  1. amino-acyl synthetase
  2. ATP
• What is the initiation codon of translation?

  AUG
• What enzyme will bound the amino acids in P-site and A-site?

  peptidyl transferase
• amino acid in P-site + amino acid in A-site = ?

  peptide bond (a type of covalent bond)
• what are the three stop codons?

  • UAA
  • UAG
  • UGA
• Three chemical parts of a nucleotide?

  1. phosphate
  2. sugar
  3. nitrogenous base
• A-T has two hydrogen bonds while G-C has three, which pairing can be separated more easily?

  A-T
• the pairing of nitrogenous bases is called

  base pairing
• nucleotides


  what is the units that are joined together to form a strand of DNA?
• building blocks of proteins


  amino acids
• source of energy aside from the carbohydrates

  • proteins
  • lipids
• absorbs visible light

  pigments