lec22

Question 1

What is the function of the sliding clamp in DNA replication?

Answer 1

A: It holds DNA polymerase onto the template strand, increasing processivity. In prokaryotes, it’s the β clamp, and in eukaryotes, it’s PCNA.

Question 2

🧬 DNA Polymerase I vs III (Prokaryotes)

Answer 2

DNA Pol III

🔧 Main builder of DNA

🔁 Uses β-clamp for high processivity

🔍 Has 3’ → 5’ exonuclease → proofreading

📍 Synthesizes leading & lagging strands

DNA Pol I

🧹 Removes RNA primers (5’ → 3’ exonuclease)

🧱 Fills in DNA after primer removal

🔍 Also has proofreading (3’ → 5’ exonuclease)

🧬 Helps process Okazaki fragments