DNA Replication

• What is the purpose of DNA replication?

  To produce identical DNA copies before cell division
• What initiates DNA replication?

  Origin of replication
• What is the role of helicase in DNA replication?

  Unwinds the DNA helix and breaks hydrogen bonds
• What do Single-Strand Binding Proteins (SSBPs) do?

  Stabilize unwound DNA
• What is the function of topoisomerase during replication?

  Relieves tension caused by unwinding
• What does primase do in DNA replication?

  Lays down RNA primers to provide a starting point
• How is the leading strand synthesized during replication?

  Synthesized continuously
• How is the lagging strand synthesized during replication?

  Synthesized in Okazaki fragments
• What is the role of DNA Ligase?

  Joins Okazaki fragments on the lagging strand
• When does DNA replication terminate?

  When all DNA has been copied
• Where does transcription occur?

  In the nucleus
• What is the start codon for translation?

  AUG
• What occurs during the initiation of translation?

  Ribosome assembles at the start codon
• What signals the termination of translation?

  Ribosome reaches a stop codon
• What are the key differences between DNA and RNA?

  • DNA:
  • Sugar: Deoxyribose
  • Strands: Double-stranded
  • Bases: A, T, C, G
  • Stability: Stable
  • RNA:
  • Sugar: Ribose
  • Strands: Single-stranded
  • Bases: A, U, C, G
  • Stability: Less stable
• What is the role of proofreading in DNA replication?

  DNA polymerase checks and corrects errors
• What is the Central Dogma of Molecular Biology?

  • DNA → RNA → Protein
  • Replication: DNA copied to DNA
  • Transcription: DNA transcribed to RNA
  • Translation: RNA translated into proteins
• What are the three main steps of DNA replication?

  Helicase, DNA Polymerase, Ligase
• What is the role of Helicase in DNA replication?

  It unzips/unwinds the DNA molecule
• What does DNA Polymerase do during replication?

  It brings in new nucleotides
• What is the function of Ligase in DNA replication?

  It zips the new DNA back together
• Why is DNA replication important?

  It ensures each new cell has identical genetic instructions
• What does "semi-conservative" mean in DNA replication?

  Old strands become part of new strands
• What information does DNA carry?

  Instructions to construct proteins and regulate activities
• What are the two processes involved in protein synthesis?

  Transcription and translation
• What happens during transcription?

  The DNA message is converted into an RNA molecule
• What occurs during translation?

  The RNA message assembles amino acids into a protein chain
• What is the Central Dogma of Molecular Biology?

  It is the foundation of all biology
• What happens during transcription in the nucleus?

  The DNA code is transferred to mRNA
• What binds to a specific section of DNA during transcription?

  RNA polymerase
• What is a codon?

  A three-base code in DNA or mRNA
• How are codons coded?

  In triplets of three bases
• What begins the process of translation?

  mRNA binds to the ribosome
• What do tRNA molecules do during translation?

  They interpret the mRNA codon sequence
• What is an anticodon?

  A three-base coding sequence in tRNA
• How does the anticodon relate to the codon?

  Each anticodon is complementary to a codon
• What are start and stop codons used for?

  To start and stop translation
• What are the steps of protein synthesis?

  1. Transcription: DNA code transferred to mRNA
  2. Translation: mRNA used to assemble amino acids into proteins
• What is the genetic code?

  • Codons: Three-base sequences in mRNA
  • Correspond to specific amino acids
  • Start and stop codons regulate translation