Concept map that describes DNA replication using the terms:
template
leading strand
DNA polymerase III
Lagging strand
DNA polymerase I
Okazaki fragment
oriC
ter
DnaB
DNA gyrase
DnaA
DNA primase
The Correct Answer and Explanation is :
Here’s the concept map description for DNA replication with the terms provided:
- oriC: This is the origin of replication in bacterial DNA. It is the starting point where the DNA replication process begins.
- DnaA: This initiator protein binds to oriC and unwinds the DNA, creating the replication bubble. This action marks the beginning of DNA replication.
- DnaB: This helicase enzyme further unwinds the DNA ahead of the replication fork to create single-stranded regions necessary for replication.
- DNA gyrase: This enzyme alleviates the tension created by unwinding, preventing DNA supercoiling, thus allowing smooth progression of the replication machinery.
- Template: The single strand of DNA that serves as a guide to synthesize a new strand of DNA, either for the leading or lagging strand.
- DNA primase: This enzyme synthesizes short RNA primers on the template strand, providing the starting point for DNA polymerase to begin synthesizing the new DNA strand.
- Leading strand: This is the continuous strand of DNA synthesized in the same direction as the replication fork moves. It is synthesized by DNA polymerase III.
- Lagging strand: The opposite strand of DNA that is synthesized discontinuously. It is formed in segments called Okazaki fragments.
- DNA polymerase III: This enzyme is responsible for the continuous synthesis of the leading strand and extends the Okazaki fragments on the lagging strand.
- Okazaki fragments: These are short segments of DNA synthesized on the lagging strand. They are later joined to form a continuous strand.
- DNA polymerase I: This enzyme removes the RNA primers on the lagging strand and replaces them with DNA nucleotides.
- ter: The termination site in bacterial DNA replication. It is where the replication machinery stops once the replication fork meets it.
300-word Explanation:
DNA replication is a vital process for cellular division and occurs in a specific sequence of steps involving many enzymes. It begins at the oriC, where DnaA binds and starts unwinding the DNA. This unwinding is further assisted by the helicase enzyme, DnaB, while DNA gyrase prevents supercoiling and tension by cutting and resealing the DNA.
The template DNA strand provides the instructions for building the complementary strand. DNA primase synthesizes RNA primers on both the leading and lagging strands. The leading strand is synthesized continuously in the direction of the replication fork, by DNA polymerase III. However, the lagging strand is synthesized discontinuously in short pieces known as Okazaki fragments, due to its direction being opposite to the replication fork movement. These fragments are later connected by DNA polymerase I, which also removes the RNA primers.
Once replication reaches the end of the DNA, the process concludes at the ter site. The overall action is to ensure that the genetic material is duplicated faithfully so that each daughter cell gets a complete copy of the genome.
Now, I’ll generate an image of this concept map.
Here is the concept map illustrating DNA replication. It includes all the key terms and processes involved. Let me know if you need any further clarifications or modifications!
