DNA Repair Mechanisms and Functions

The video tutorial by Sahir from Easy Peasy discusses DNA repair mechanisms, focusing on how DNA gets damaged and the body's repair systems. It covers endogenous and exogenous pathways of DNA damage, the consequences of unrepaired DNA, and details three repair systems: mismatch repair (MMR), base excision repair (BER), and nucleotide excision repair (NER). Each system's process and the proteins involved are explained, highlighting the importance of these mechanisms in maintaining genomic stability.

What are the two main pathways through which DNA can be damaged?

• Endogenous and Exogenous

• Internal and External

• Primary and Secondary

• Direct and Indirect

What could happen if DNA damage is not repaired?

• Enhanced DNA synthesis

• Genomic stability

• Genomic instability

• Increased cell division

Which repair system is responsible for fixing mismatches in DNA bases?

• Base Excision Repair

• Mismatch Repair System

• Nucleotide Excision Repair

• Double Strand Break Repair

What is the role of MutS protein in the Mismatch Repair System?

• It repairs double strand breaks

• It removes the incorrect nucleotide

• It recognizes the bulge or error

• It adds new nucleotides

In the Mismatch Repair System, what is the function of MutH protein?

• It synthesizes new DNA strands

• It detects mismatches

• It adds methyl groups

• It acts as a scissor to cut the DNA

What type of DNA damage does the Base Excision Repair system address?

• UV-induced pyrimidine dimers

• Double strand breaks

• Mismatched bases

• Hydrolysis, oxidation, and alkylation

Which enzyme removes the incorrect base in the Base Excision Repair system?

• DNA polymerase

• AP endonuclease

• DNA ligase

• DNA glycosylase

What kind of damage does the Nucleotide Excision Repair system primarily fix?

• Hydrolysis and oxidation

• Double strand breaks

• UV-induced pyrimidine dimers

• Mismatched bases

In the Nucleotide Excision Repair system, which protein detects the damage in eukaryotes?

• UVRA

• AP endonuclease

• XPC

• MutS

What is the final step in the Nucleotide Excision Repair process?

• Removal of damaged DNA

• Detection of damage

• Joining of new and old DNA strands

• Synthesis of new DNA