summary of central dogma

• The Central Dogma of Molecular Biology:

  • DNA undergoes replication, transcription to RNA, translation to proteins
  • Nucleic acids are formed by N-bases + sugar-phosphate backbone, leading to DNA
  • Nucleotide structure: phosphate + sugar + base
  • Nucleoside structure: sugar + base
  • Sugar differences: deoxyribose in DNA (lacks Oxygen on 2') and ribose in RNA (has Oxygen on 2')
  • Nitrogenous bases: Pyrimidines (Cytosine, Uracil in RNA, Thymine in DNA) and Purines (Adenine, Guanine)
  • Complementary bases: Pyrimidines pair with Purines
  • Nucleotides are linked by phosphodiester bonds to form nucleic acids
  • Hydrogen bonds bond N-bases (2 HB for AT pair, 3 HB for CG pair)
  • Sugar-phosphate bonds form the backbone, while N-bases are the appendages
  • DNA sequence depends on N-bases
• DNA Replication:

  • Models: conservative, semi-conservative (best model), dispersive
  • Proteins involved: Helicase, Single-strand binding proteins, Topoisomerase, RNA Primase, DNA polymerase I and III, Ligase
  • Process: Initiation, Elongation, Termination
• Transcription:

  • Terms: RNA polymerase, mRNA, Promoter, σ/transcription factor
  • Process: Initiation, Elongation, Termination
• Termination Processes in Prokaryotes and Eukaryotes:

  • Prokaryotes couple transcription and translation, while Eukaryotes involve mRNA processing
  • Eukaryotic mRNA processing includes Guanine nucleotide cap, poly-A tail, RNA splicing, and alternative splicing
• Translation:

  • Terms: codon, amino acid, peptide, polypeptide, protein
  • Machineries: mRNA, tRNA, Ribosome, rRNA, Initiation factors, Release factor
  • Process: Initiation, Elongation, Termination
• Post-Translational Modifications:

  • Proteins undergo modifications in the Golgi apparatus