What is DNA Polymerase? Questions

DNA polymerase, sometimes referred to as DNA replicase, is an enzyme that synthesizes DNA—that is, it copies existing DNA and creates new strands of it. There are several types of DNA polymerases, each with specific roles. In this article, we’ll take a look at the types of DNA polymerases, how they’re used in biotechnology and medicine, and what their role is in the process of copying (or “replicating”) existing strands of DNA.

What is DNA polymerase?

DNA polymerase is an enzyme. It is one of the most important enzymes in all living cells, because it catalyzes the process by which DNA replicates. Without this enzyme, cells could not divide or grow. The main function of DNA polymerase is to synthesize DNA during cell division, but it also helps in other processes such as transcription (the reading of genes into RNA) and repair when there are breaks in your chromosomes caused by things like radiation or chemicals.

The two types of DNA polymerases are called pol I and pol II; they differ in how many copies they make per second (pol I takes about five minutes per copy; pol II takes about 90 seconds per copy). However, both type IIs are more efficient at copying damaged nucleotides than type Is

What does DNA polymerase do?

DNA polymerase is an enzyme that helps to create new DNA molecules. It is used in all living organisms, from bacteria to plants and animals, including humans.

The function of DNA polymerase is essential for life as we know it. Without it, our cells would not be able to divide or reproduce themselves—and thus neither would we!

DNA polymerase plays a role in three main functions: replication (copying DNA), repair (fixing damaged or broken strands), and transcription (reading genes into RNA).

How does DNA polymerase work?

The enzyme DNA polymerase catalyzes the polymerization of deoxyribonucleotides into DNA. It is a key enzyme in the replication of DNA, and it is also a part of the DNA replication complex.

DNA polymerases are classified according to their composition, mechanism, and how they function:

  • Class I enzymes include many types of bacteriophages that infect bacteria and reverse transcribe viral RNA into double-stranded DNA. These enzymes typically require an auxiliary protein (primase) to initiate synthesis. The enzyme can work in either direction—away from or toward free hydroxyl groups at each end of its template strand (leading/lagging). This class includes T7 phage plus many others that share its properties.
  • Class II consists exclusively of eukaryotic mitochondrial DNAPs; these are generally G+C rich with small active sites without proofreading activity but high processivity due to large subunits; they use different base pairs than prokaryotic systems do during replication because they lack 5-methylcytosine residues that would otherwise interfere with their specialized processivity factors;
  • Class III enzymes replicate alphoid RNA templates without proofreading activity but with reasonable processivity; these enzymes are thought to be descended from some kind of primordial predecessor involved in monomer addition reactions during prebiotic evolution rather than existing as part of living cells today although some argue otherwise based on indirect evidence suggesting otherwise; there exists one known example (called Pfu) which enables researchers studying this family structure thanks largely due its relatively easy access compared other related systems found elsewhere around planet Earth

How is DNA polymerase used in biotechnology and medicine?

In biotechnology and medicine, DNA polymerase is used to repair damaged DNA. It can be used to clone DNA by taking a specific piece of DNA and making a copy of it. When you are sequencing or amplifying your DNA, you will use the polymerase chain reaction (PCR). This is where you take one small piece of the gene and amplify it so that there is enough for further analysis or testing.

In biotechnology, this enzyme can be used with restriction enzymes in order to create libraries from bacterial species or other organisms found in nature.

How many different types of DNA polymerase are there? Which are the main ones?

There are nine different polymerases that have been identified in humans, so far. But only three of them play a significant role in DNA replication:

DNA Polymerase I (Pol I) is responsible for transcribing the RNA component of chromosomes into DNA. It is also used to repair damages in the DNA, although it can’t add new information like Pol III can do.

DNA Polymerase II (Pol II) helps synthesize messenger RNA from DNA templates during transcription—in other words, it reads off genetic information from the nucleus and makes mRNA copies of those sequences to send out into cytoplasm where they’ll be translated by ribosomes into proteins or other types of RNAs.

DNA Polymerase III (Pol III) takes over after transcription has occurred and starts replicating your genome by adding A’s, C’s, T’s and G’s onto both strands at specific points along each side of your double helixes; this is called semi-conservative replication because it creates two identical copies while conserving some original bases as well

Is there a difference between DNA polymerase I and DNA polymerase II? If so, what is it?

Polymerase I and II are two different types of DNA polymerases. DNA polymerases are enzymes that synthesize new strands of DNA in the process of replication. While they have the same name, they have different functions and structures.

DNA polymerase I is a proofreading enzyme that adds nucleotides to the 3′ end of a growing strand if it finds an incorrect base pair during replication. This enzyme also has exonuclease activity, which means it removes unwanted nucleotides from newly replicated DNA strands before adding more nucleotides to them, making sure only correct base pairs are present in the newly synthesized strand.

DNA polymerase II is a non-proofreading enzyme that attaches new nucleotides to both ends of single-stranded DNA without checking for mistakes during replication; this allows it to create blunt or staggered ends on both sides rather than just one side like most other DNA polymerases do (with T4 being an exception).

It also does not have any exonuclease activity like other types do so there will always be some unpaired bases at each end after synthesis has finished being completed by this particular enzyme type!

There are several types of DNA polymerases, each with specific roles.

There are several types of DNA polymerases, each with specific roles. Some DNA polymerases synthesize DNA from an existing template and others use a primer to initiate synthesis; they’re often distinguished by their means of nucleotide recognition.

DNA Polymerase I is the main enzyme used in DNA replication and repair; it adds deoxyribonucleotides onto a pre-existing strand at a rate of around 100 base pairs per second. The enzyme can only add nucleotides one at time–it cannot skip ahead or backtrack along the strand.

This property makes it ideal for replicating long strands because it doesn’t have to pause frequently as other enzymes do in order to readjust their position on the strand before adding more nucleotides.


As you can see, there are many different types of DNA polymerases in nature. But they’re all united by their job as the catalysts for copying DNA, which is a vital process in life. Among the other processes that depend on DNA replication are cell division and protein synthesis; without these two processes working properly, cells would not be able to maintain themselves or grow and develop as necessary for organisms.

In addition to this important role in organisms’ lives, DNA polymerases also have significant research potential because they can be used as molecular tools to create new sequences of genetic code with specific properties that scientists want to study more closely—for example, by replicating genes encoding proteins found only rarely in nature but useful for human health.


  1. http://www-lehre.img.bio.uni-goettingen.de/
  2. http://dnareplication.cshl.edu/content/free/chapters/15_wang.pdf
  3. www.informatics.indiana.edu/…/lecture_notes_19b.pdf