DNA Polymerase
DNA Polymerase is an enzyme that allows new cells in the body to be created and strands of DNA to be duplicated. These enzymes store information from a cell as the divides, allowing the new cell to contain the same information. When the enzymes duplicate information from the original cell before cell division, it is called polymerization. Additionally, DNA Polymerase are useful when duplicating DNA. These enzymes can use strands of DNA as a guide, or template, and assist in creating a duplicate strand. The enzymes are also useful in cell repair. With the ability to assist in cell reproduction, these enzymes can also help prevent the death of cells.
When replicating DNA, DNA Polymerases add nucleotides to a part of the DNA strand that match the guide, or template, strand. The original DNA strand creates a replication fork, which allows the DNA Polymerase to do the job of synthesizing new DNA. Essentially using a piece of one strand of DNA to make another, much like a copy machine would for a document, in a way. In order for this DNA replication to occur, there has to be a strand of DNA that creates a replication fork. Without the replication fork, nothing can happen, because the DNA strand cannot be created from scratch.
Some DNA Polymerases can correct DNA errors. When building a new strand, there are some of these enzymes with an ability known as proofreading. Proofreading allows the DNA Polymerase to recognize and error, remove it, and replace it. The result is an error-free strand of DNA. Not all of the enzymes possess this ability. Since it is only possible for these enzymes to use existing strands of DNA as a guide or template, error correction only works with mistakes. In other words, it is not possible to make something different in the replication than it is in the original.
There are seven family subclasses of DNA Polymerase. Some of these subclasses have been thoroughly studied, such as Family Subclass I. In this subclass there are a number of bacteria polymerase, and it includes both replicative and repair DNA Polymerases. Other subclasses have not been studied a great deal, so more exploration is required to garner knowledge. An example is Family Subclass IV, of which little is known. There is even a subclass-Family Subclass VII-that uses RNA as a guide, or template, for replicating strands of DNA. Read the rest of this entry »
DNA Replication
All living organisms have a process within them called DNA Replication. What is DNA Replication, you ask? It is an important process by which the root identity of an organism copies itself, or makes more of itself.
DNA, or deoxyribonucleic acid, is the genetic sequence or code that makes each living organism unique on the molecular level. DNA Replication involves this microscopic sequence or code creating more of itself. A single strand of DNA molecules undergoes DNA Replication and the result is another identical strand.
DNA Replication usually occurs within cells. There is a specific area within the cell, called a genome, in which this fundamental process occurs. The DNA strands unravel and rearrange themselves at the genome. The synthesis of these strands and proteins is how the DNA within cells begins to extend and ultimately reproduce itself.
The process of DNA Replication can also occur on the outside of a cell, which is called ‘in vitro.’ The synthesis that would occur within a cell has to be initiated artificially using what is called DNA primers. The process of polymerase allows the DNA primer to locate and copy a specific strand within a pool of DNA molecules. This is a common lab procedure.
When DNA is replicated, the double stranded structure or the DNA, which is coiled together, is separated. During this separation, each side of the strand is recreated individually. The new strands turn out to be identical, and the chance that there is any error is incredibly small.
DNA is one of the major building blocks of life. It is so tiny, yet it is important to all living things. It is a rather complicated process at first glance, however, it is easy to understand the need for DNA Replication.
This naturally occurring process is crucial to the survival of life on earth as we know it. The reproduction of all life depends on the ability of DNA to make copies of itself. For example, when a woman become pregnant, proper DNA replication has to occur, otherwise the baby will not survive or there will be deformities. Babies start off as a cell, and the cell divides. Before the cell divides, in order for the baby to properly develop, the DNA must replicate itself accurately. In the rare case that the development does not occur properly, there will be something missing in the baby’s genetic code. Read the rest of this entry »