Question

Assuming that each replication fork moves at a rate of 500 base pairs per second, how long would it take to replicate the E. coli chromosome (with 4.6 million base pairs) from a single origin of replication?

Short answer

It would take approximately 153 minutes to replicate the entire E. coli chromosome with a single origin of replication at a rate of 500 base pairs per second.

Step-by-step solution

Identify the given values

The given values are: - Total base pairs in the E. coli chromosome: 4,600,000 base pairs - Rate of replication: 500 base pairs per second

Apply the formula to find the time

The formula for the time required to replicate the chromosome is: Time = (Total base pairs) / (Rate of replication)

Substitute the given values into the formula

Plug in the given values into the formula: Time = (4,600,000 base pairs) / (500 base pairs per second)

Calculate the time

Divide the total base pairs by the rate of replication to find the time: Time = 4,600,000 / 500 Time = 9200 seconds

Convert the time to appropriate units

Convert the time in seconds to minutes by dividing by 60: Time = 9200 seconds / 60 Time = 153.33 minutes To get a more convenient time unit, we can round it to the nearest minute: Time = 153 minutes To replicate the entire E. coli chromosome with a single origin of replication at a rate of 500 base pairs per second, it would take approximately 153 minutes.

Key concepts

Replication Fork Speed

The replication fork speed in DNA replication is a critical factor that determines how quickly a cell can duplicate its genome. In the context of E. coli, a bacterium with a relatively small genome, each replication fork moves at an impressive rate of 500 base pairs per second. This speed allows the bacteria to quickly replicate its chromosome, ensuring a fast division time, which is a key element of its rapid growth in favorable conditions.

The replication fork speed is a result of the coordinated action of various enzymes, including DNA helicase, which unwinds the DNA helix, and DNA polymerase, which synthesizes the new DNA strands using the unwound strands as templates. The efficiency and speed of these enzymes are finely tuned to E. coli's lifecycle and ensure that genome replication is both fast and accurate, which is vital for maintaining genetic stability across generations.

Chromosome Base Pairs Calculation

To fully understand the scope of DNA replication in E. coli, it is important to comprehend how chromosome base pairs calculation plays a role. The E. coli chromosome consists of approximately 4.6 million base pairs, which is a measurement of the amount of genetic information it contains. This number is fundamental for calculating the total time required for DNA replication.

In the given exercise, this calculation is essential to determine the overall replication time. When given the total number of base pairs, scientists or students can estimate the amount of work that DNA polymerase, the enzyme responsible for synthesizing new DNA strands, needs to perform. This serves as the basis for figuring out the duration of the replication process when combined with the replication fork speed, thus linking these two critical concepts in understanding DNA replication in E. coli.

Genetic Replication Time

Genetic replication time is the duration it takes for a cell to completely replicate its genome. As seen in the textbook exercise, calculating this time involves using the total number of base pairs in the chromosome and the replication fork speed to derive an estimated time for replication completion.

In E. coli, with 4.6 million base pairs and a replication rate of 500 base pairs per second, the process takes around 9200 seconds, which equates to roughly 153 minutes as solved step by step in the provided solution. This time is critical for the bacteria's ability to reproduce and maintain its population, particularly in environments where rapid growth is necessary to exploit available resources or colonize new areas. Understanding such timing is not only relevant for academic purposes but also has practical implications in fields like microbiology and biotechnology, where controlling the growth of bacterial populations can be crucial for various applications.