Essay about The Question of Biology is "Why?"

Multiple enzymes work together to help your DNA duplicate. Helicase, one of these enzymes used to help replicate DNA, uses energy from the ATP to break apart the hydrogen bonds holding the bases together. This allows for the two parental strands of DNA to unwind and form two replication forks. Primase, also an enzyme used in DNA replication, copies a DNA parental strand by making an RNA strand complementary to it. Primase is only active when another protein is present. There are two DNA polymerases: DNA polymerase III and DNA polymerase I. DNA polymerase III catalyzes the chemical reactions for polymerization of nucleotides. DNA polymerase I is involved in removing RNA after replication. If DNA polymerase makes a mistake during synthesis,

First, let’s understand where DNA replication is happening along the DNA. The whole region of unwound DNA is called the

Telomeres make up the tips of linear chromosomes and function to protect and stabilize the chromosomes from degradation (Pierce 2014). There are other functions, but the primary one is protection. At each replication, DNA shortens by just a few base pairs due to the nature of replication in eukaryotes (who have linear chromosomes). The two strands of DNA are synthesized at different rates, creating a leading strand and a lagging strand. The leading strand is replicated quickly and fluidly in a 5’ to 3’ direction, as seen in Image 1. The lagging strand is replicated in a backstitch patter. Primers are placed along the DNA strand and DNA polymerase replaces them with segments of DNA. It can only do this, though, if a 3’-OH group is present. The 3’-OH group precedes the primer, and would sit just to the right of the green primers in Image 1. No 3’-OH group would be present at the end of the chromosome because it only exists on one side of the primer. The area where the primer is sitting would not be replicated, and thus the DNA would shorten. Tandem sequences of noncoding DNA sit at the ends of the

The main purpose of primase in DNA replication is to synthesize RNA; it makes RNA oligonucleotides that are used as primers for DNA synthesis. Without this, DNA Polymerase could not start a new chain of DNA, so primase serves as a starting point for replication. After Helicase breaks the strands apart, primase comes in to add short, new RNA nucleotide chains (about 10 nucleotides long) to the template strand. Then the DNA polymerase can add new DNA nucleotides to the strand forming new DNA strands. Without the correct functioning of this enzyme, the Polymerase could not carry out its functions, so the synthesis of a new DNA strand would be interrupted, causing no new DNA to

Finally, all the nucleotides are joined to form a complete polynucleotide chain using DNA polymerase. The two new DNA molecules form double helices.

In this essay, we will observe the structure of DNA, DNA replication and how scientist visualizes DNA. First off, DNA or deoxyribonucleic acid, resides in the nucleus of every living cell. DNA structure was understood more by Rosalind Franklin with the help of other biologists later on during the year, to describe the twisted ladder or double helix structure of DNA. It must go through a complex task called DNA replication to duplicate itself to form two identical DNA molecules. However, for us to visualize DNA with a naked eye, biologists use modern laboratory techniques that allow them to extract DNA from tissue samples.

The mRNA is then released once the RNA polymerase reaches the end of the gene. In the

During DNA replication, DNA polymerase is unable to replicate the 3’ end of linear chromosomes because replication can only proceed in the 5’ to 3’ direction and requires a primer (Garavis, 2013). Telomerase is able to recognize the presence of the G-rich repeat sequence. It elongates he strand in the 5’ to 3’ direction and adds additional repeats, using the RNA template in the enzyme as it moves past the template strand. DNA polymerase, which carries a DNA primase as one of its subunits, completes the lagging strand. This step successfully completes original information at the ends of linear chromosomes (Garland Science, 2009). Without telomerase, telomeres would shorten, resulting in aging. The shortening of telomeres as a person ages leads to higher likelihood of heart disease, bone problems, cancer, and the more obvious, aged skin (Chojnowski, 2015). This process can be observed in Figure 1.

DNA replication is described as semi-conservative. It is semi-conservative because the replication of one helix results in two daughter helices each of which contains one of the original parental helical strands. Furthermore, it is semi-conservative because the two new daughter DNA molecules are “half old” and “half new”; this means that half the original DNA molecule is saved, or conserved in the daughter DNA molecules.

PCR (polymerase chain reaction) is used to zero in on a certain gene of choice. First, the DNA is heated to 55C, and then heated to 95C, which splits the double-stranded DNA into single-stranded DNA. The mixture is then brought back down to 55C in which specific primers anneal to the strands of DNA. Once that process is completed, the mixture is then heated to 72C, which causes TAC polymerase to grab onto random oligonucleotides. Finally, the mixture is brought back up to 95C to allow the DNA to split again. This process repeats a total of 32 times resulting in millions of copies of the gene in question. The primers added to the mixture only attach to specific sequences in order to insure that the gene the experimenter wants is the only one that copies. The process of PCR allows for the proliferation of the gene in question to reach a high

Being double stranded means that when the DNA-helicase enzyme unzips it, information can be copied from both strands at the same time. DNA-polymerase is responsible for attaching free DNA nucleotides to the open DNA strands. The DNA-helicase enzyme will not stop till it reaches the end of the strand. Same as the DNA-polymerase. When DNA is copied from both the complementary strand and the template strand, this process is called semi-conservative replication.

The ongoing scientific investigation of how exactly evolution occurred and continues to occur has been an argumentative idea amongst society since Darwin first articulated it over a century ago. The scientific basis of evolution accounts for happenings that are also essential concerns of religion; both religion and science focus on the origins of humans and of biological diversity. For instance, in the reading “Truth Cannot Contradict Truth,” Pope John Paul II, addressing the Pontifical Academy of Science, discussed the matter of God as creator of man. The Pope explains that men cannot relate to animals because men are superior. The reasoning for that is because God created humans under his likeness. What the church is saying about mankind

DNA replication was a difficult subject for me to understand and internalize throughout the course. I struggled to answer the given practice questions and by attempting to learn the material quickly, I tried to memorize everything before the exam.

Biology is the scientific study of living things. Chemistry is the scientific study of matter and how it changes. The fields of science where biology and chemistry meet are biochemistry or molecular biology. Scientists in these fields examine how chemicals and molecular components come together in a way that is balanced enough to create something that has not been discovered on any other planet: life. DNA is the molecule that accounts for the chemical unity and the physical diversity between humans and all other known species.

Biological evolution is the name for the changes in gene frequency in a population of a species from generation to generation. Evolution offers explanation to why species genetically change over years and the diversity of life on Earth. Although it is generally accepted by the scientific community, Charles Darwin’s theory of evolution has been studied and debated for several decades. In 1859, Darwin published On The Origin of Species, which introduced the idea of evolutionary thought which he supported with evidence of one type of evolutionary mechanism, natural selection. Some of the main mechanisms of evolution are natural selection, mutation, and genetic drift. The idea that all life on Earth shares a common ancestor has been around for