D1.1.3 Role of helicase and DNA polymerase in DNA replication Flashcards
(18 cards)
What bonds does DNA polymerase form during DNA replication?
DNA polymerase forms strong covalent bonds between the sugar and phosphate groups of adjacent nucleotides.
What is the function of helicase in DNA replication?
Helicase unzips the DNA by breaking hydrogen bonds between complementary bases and separating the two strands.
What type of bonds does helicase break during DNA replication?
Helicase breaks hydrogen bonds between complementary bases, not covalent bonds in the DNA backbone.
What are Okazaki fragments?
Okazaki fragments are short segments of DNA synthesized on the lagging strand, which are later joined by DNA ligase.
What happens during DNA synthesis on the leading strand?
DNA synthesis on the leading strand is continuous.
What is the function of the sugar-phosphate backbone in DNA?
The sugar-phosphate backbone provides structural support and stability to the DNA molecule.
How does helicase create the replication fork?
Helicase moves along the DNA, breaking hydrogen bonds, which creates the Y-shaped replication fork for new strand synthesis.
How does DNA polymerase ensure correct nucleotide pairing?
DNA polymerase ensures correct nucleotide pairing through complementary base pairing (A with T, C with G).
What is the difference between the roles of helicase and DNA polymerase?
Helicase unwinds the DNA, while DNA polymerase builds the new strands.
Give an example of a real-world application of DNA polymerase.
DNA polymerase is used in PCR (polymerase chain reaction) for DNA replication and amplification in genetic testing and forensics.
What is helicase?
Helicase is a ring-shaped enzyme that unzips DNA by breaking hydrogen bonds between base pairs.
Why are helicase and DNA polymerase important for genetic continuity?
They ensure that each new cell receives an exact copy of the DNA, preserving genetic information across generations.
What is the role of DNA polymerase in DNA replication?
DNA polymerase synthesizes new DNA strands by adding nucleotides to a growing chain, using the original strand as a template.
What are the three key functions of DNA polymerase?
- Complementary base pairing
- Covalent bond formation of the sugar-phosphate backbone
- Proofreading/mismatch correction.
How many nucleotides does DNA polymerase add per second in humans?
DNA polymerase adds about 50 nucleotides per second during replication in humans.
What is the proofreading function of DNA polymerase?
The proofreading function of DNA polymerase identifies and corrects mismatched bases, reducing replication errors.
In which direction does DNA polymerase synthesize new DNA strands?
DNA polymerase synthesizes new strands in the 5’ to 3’ direction.
What is the role of helicase in the context of PCR (polymerase chain reaction)?
In PCR, helicase is used to unzip the DNA strands, allowing DNA polymerase to replicate the target sequence.
