Explain in a narrate way the sequence of events occuring in DNA replication in helicase
A very very short explanation
In the process of DNA replication, helicase plays a crucial role in unwinding the double-stranded DNA molecule. Helicase is like a molecular machine that moves along the DNA strand, separating the two strands by breaking the hydrogen bonds between the base pairs.
Firstly, the helicase enzyme binds to a specific site on the DNA molecule called the origin of replication. Once bound, it begins to unwind the DNA helix, moving in one direction along the strand.
As the helicase moves along, it continues to separate the two DNA strands, exposing the single-stranded template DNA. This single-stranded DNA serves as a template for the synthesis of new DNA strands.
The separation of the DNA strands by helicase creates a region known as the replication fork. The replication fork is like a fork in the road, where the two strands of the DNA molecule separate and new strands are synthesized.
Once the DNA molecule is unwound, other proteins and enzymes come into play, such as DNA polymerase, which adds complementary nucleotides to each single-stranded template DNA molecule. These nucleotides pair up with the exposed bases on the template strand (A with T and C with G) to create new, identical DNA strands.
In summary, helicase unwinds the double-stranded DNA molecule, creating a replication fork where new DNA strands are synthesized. It plays a crucial role in DNA replication by separating the two DNA strands and exposing the template DNA for the synthesis of new strands.
1. The helicase enzyme binds to the DNA double helix at a specific sequence called the origin of replication.
2. Once bound, the helicase starts unwinding the DNA helix by breaking the hydrogen bonds between the base pairs.
3. As the helicase moves along the DNA, it continues to separate the two strands, creating a replication fork.
4. Single-strand binding proteins (SSBPs) bind to the separated strands, preventing them from reannealing and stabilizing the DNA structure.
5. With the DNA strands unwound, DNA polymerase can now access the template strand and begin synthesizing new complementary strands.
In summary, helicase is responsible for unwinding the DNA double helix to form a replication fork, allowing DNA polymerase to synthesize new strands.