Okazaki Fragments vs Lagging Strand

“Okazaki fragments” and “lagging strand” are terms often used in chemistry. You probably heard a lot about okazaki fragments and lagging strand in your chemistry class. Well, that is only if you are intently listening to your professor. This article serves as a refresher for what okazaki fragments and lagging strand are all about.

Okazaki fragments and lagging strand are discussed as long as DNA replication is concerned. First of all, DNA replication is defined as the biological process that occurs in all living organisms and copies their DNA. DNA, on the other hand, is the basis for biological inheritance.

During DNA replication, okazaki fragments are formed. These okazaki fragments look relatively short. They are considered as the end products or the newly synthesized DNA fragments that are formed on the lagging strand. Simply put, the okazaki fragments are formed on the lagging strand. A lagging strand is defined as the DNA strand that is replicated discontinuously from the five-foot to three-foot direction. The five-foot to three-foot direction is the directionality in molecular biology.

Okazaki fragments are complementary to the lagging strand. Without them, there will be no formation of short, double-stranded DNA sections. If we are to determine the length of the okazaki fragments, they range from 1,000 to 2,000 nucleotides long in Escherichia coli, a kind of bacteria commonly found in the gut of warm-blooded organisms. Okazaki fragments measure between 100 to 200 nucleotides long in the eukaryotes, organisms that have complex cell structures.

Each of the okazaki fragments are separated by RNA primers. And if the RNA primers are removed, the enzyme called ligase will be connecting the okazaki fragments together in order to form a newly synthesized complementary strand.

As we have said earlier, okazaki fragments and lagging strand are complementary with each other. However, there is another DNA strand that plays a very important role during the DNA replication process. It is called the leading strand. If the lagging strand is defined as being replicated discontinuously, the leading strand goes the other way around. It is being replicated continuously. The presence of the leading strand enables the parent double-stranded DNA to be unwound. Simply put, the route offered by the leading strand is continuous.

During DNA replication, the strands should be bonded into a five-foot to three-foot direction. With the leading strand’s undisturbed or continuous route, there will be no problems. But when it comes to the lagging strand, since it comes to the antiparallel direction of the DNA, it cannot be continuous. To compensate, the lagging strands are produced as short strands with the complementary help of the okazaki fragments. It is fairly normal that the DNA strands run in opposite directions because the structure of the DNA is a double helix. Since the lagging strand is on the antiparallel direction, its polymerase functions by working back towards the replication fork and in short pieces.

The okazaki fragments and other associated processes in the DNA replication process were discovered by Kiwako Sakabe and Reiji Okazaki in the year 1966. They had made a research regarding the DNA replication process of the bacterium, Escherichia coli.

Summary:

1. “Okazaki fragments” and “lagging strand” are terms often used in chemistry.
2. Okazaki fragments and lagging strand are terms in the DNA replication process.
3. Okazaki fragments are relatively short strands. They are the end products or the newly synthesized DNA fragments that are formed on the lagging strand.
4. A lagging strand is defined as the DNA strand that is replicated discontinuously from the five-foot to three-foot direction. The five-foot to three-foot direction is directionality in molecular biology.
5. The Okazaki fragments and other associated processes in the DNA replication process were discovered by Kiwako Sakabe and Reiji Okazaki in the year 1966.

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