Fill in the blanks by using the correct term/words. 1. _ Enzyme that unwinds DNA 2. Fragments of copied DNA created on the lagging strand 3. The strand that is copied in a continuous way, from the 3′ to 5′ direction 4. Binds Okazaki fragments 5. Builds a new DNA strand by adding complementary bases 6. Stabilizes the DNA molecule during replication 7. Strand that is copied discontinuously because it is traveling away from helicase 8. _ Initiates the synthesis DNA by creating a short RNA segment at replication fork
The Correct Answer and Explanation is:
Here are the correct terms to fill in the blanks:
- Helicase – Enzyme that unwinds DNA
- Okazaki fragments – Fragments of copied DNA created on the lagging strand
- Leading strand – The strand that is copied in a continuous way, from the 3′ to 5′ direction
- DNA ligase – Binds Okazaki fragments
- DNA polymerase – Builds a new DNA strand by adding complementary bases
- Single-strand binding proteins – Stabilizes the DNA molecule during replication
- Lagging strand – Strand that is copied discontinuously because it is traveling away from helicase
- Primase – Initiates the synthesis of DNA by creating a short RNA segment at replication fork
Explanation
DNA replication is a fundamental biological process during which a cell makes an exact copy of its DNA before cell division. The process begins at specific sites on the DNA molecule known as origins of replication.
- Helicase is the enzyme responsible for unwinding and separating the two strands of the DNA double helix by breaking the hydrogen bonds between the bases. This creates a replication fork, where replication begins.
- Okazaki fragments are short DNA sequences synthesized discontinuously on the lagging strand. Since DNA polymerase can only build in the 5′ to 3′ direction, these fragments form as the replication fork opens further.
- The leading strand is synthesized continuously toward the replication fork. This strand is complementary to the 3′ to 5′ parent strand, allowing DNA polymerase to follow the helicase without interruption.
- DNA ligase plays a crucial role in sealing the nicks between Okazaki fragments, forming a continuous DNA strand.
- DNA polymerase is the main enzyme that adds nucleotides to the growing DNA strand by matching complementary bases to the template strand.
- Single-strand binding proteins bind to the separated DNA strands to keep them apart and prevent reformation of the double helix during replication.
- The lagging strand is synthesized in pieces because it runs in the 5′ to 3′ direction away from the replication fork, requiring multiple RNA primers.
- Primase creates RNA primers, short RNA sequences that provide a starting point for DNA polymerase to begin synthesis.
These components work together in a highly coordinated way to ensure accurate and efficient DNA replication.
