Essay about The Question of Biology is "Why?"

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In biology, one only comes to know so much about a subject before one begins to compare it to other things. As humans, we are comparative by nature—always wondering what is the best between multiple things (if it even is) and why. That is why we do it, ultimately. We feel that we must answer the question “Why?” In this biographical paper, I will be analyzing two very different processes: DNA Replication and the Polymerase Chain Reaction (PCR). It is that each of these individual processes carries much importance. DNA replication is important in the life of a cell, more so the division, because when a cell divides both of the daughter cells need identical DNA to function properly. PCR is important in that it allows amplification of DNA and …show more content…

To understand how DNA is replicated we must first look at how DNA is built. DNA is built in an antiparallel structure, which means that one of the two strands runs from 5’ to 3’, and the other strand runs from 3’ to 5’. Now, we can look at how DNA replication begins. DNA replication begins by unwinding the two DNA strands; an enzyme called helicase accomplishes this. This enzyme uses energy from ATP to unwind the template strand, but like any other process it encounters problems that it must overcome. When DNA is unwound a phenomena called supercoiling can occur—when the DNA is unwound the DNA helix will continue to coil over in space. To overcome this an enzyme called DNA gyrase that helps in relieving the torque that is produced by the unwinding of DNA; this enzyme essentially prevents the helix from supercoiling by changing the topological state of the helix. This enzyme is known as a topoisomerase. To keep the unwound DNA strands from re-biding, a protein called single strand binding protein (SSB) temporarily binds to each template and waits for DNA primase to relieve its position on the strand. DNA primase creates a short RNA sequence on the DNA template strand so that DNA polymerase can make a copy of that DNA strand. This process is one within itself, because it can occur (and does) on either strand (3’ to 5’ or 5’ to 3’) it must lay down primer

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