Week 2: Dna Replication And Recombination Flashcards
What is DNA replication?
Copying of DNA occurring during mitosis and meiosis
What is DNA recombination?
Exchange of genetic material that helps drive evolution via meiosis and can occur as part of DNA repair
Define replication.
The action or process of reproducing or duplicating
Define recombination.
The process of recombining things
What is the significance of DNA replication in cells?
All cells maintain their DNA (hereditary) material from one generation to the next
What does ‘semi-conservative’ replication mean?
Each daughter strand contains one strand from the original (parental) strand and one new strand of DNA
What are the base pair matching rules in DNA replication?
A pairs with T and G pairs with C
List the seven key components of DNA replication.
- dNTPs
- DNA helicase
- Single-stranded DNA binding proteins
- DNA topoisomerase
- DNA polymerase
- DNA primase
- DNA ligase
What is the role of DNA helicase?
Unwinds and separates DNA to allow access for DNA polymerase
What do single-stranded DNA binding proteins do?
Prevent the DNA from sticking to itself and blocking copying
What is the function of DNA polymerase?
Carries out DNA synthesis by adding nucleotides in the 5’ to 3’ direction
How does DNA polymerase proofread its work?
It checks for correct base addition and corrects errors if found
What is the ‘winding problem’ in DNA replication?
Local winding of DNA due to the rapid action of DNA polymerase and helicase
What is the role of DNA topoisomerase?
Helps relieve supercoiling and DNA stress during replication
What is the purpose of RNA primers in DNA replication?
Provide a 3’ OH group for DNA polymerase to initiate DNA synthesis
What are Okazaki fragments?
Short segments of DNA synthesized on the lagging strand during replication
What is the replication fork?
The area where the DNA double helix is unwound and replication occurs
During which process does DNA recombination typically occur?
Meiosis and homologous recombination repair
What is homologous recombination?
Genetic exchange that takes place between a pair of homologous DNA sequences
What is a Holliday junction?
A structure formed during DNA recombination where two DNA molecules cross over
What role does RecA protein play in DNA recombination?
Enables a DNA single strand to pair with a homologous region of DNA double helix
What is the significance of recombination in genetics?
It generates genetic diversity and maintains genome integrity
Fill in the blank: DNA recombination is essential for _______.
[generating genetic diversity and maintaining genome integrity]
True or False: DNA replication occurs only during mitosis.
False
What is the estimated time for one DNA polymerase to copy the entire human genome?
67 to 133 days
