Throwback Thursday, where, essentially I post old writing samples, essays and short stories that I dig up from my pile of hoarded papers and school assignments or from the depths of my computer. So everyone can see how my writing has changed/improved over the years.
Chapter 4 Project:
Similarities and Differences of Prokaryotic and Eukaryotic DNA Report
In Biology, it is common knowledge that though similar, prokaryotic and eukaryotic cells are quite different. Along with the similarities and differences between the cells in general, there are also similarities and differences between the DNA in each of the cell types.
The differences between the DNA of each cell type are important to the function and structure of each. Structure wise, eukaryotic DNA is arranged in a linear fashion, whereas prokaryotic DNA is arranged in a circular fashion, as well as being supercoiled.
Eukaryotic DNA is not supercoiled, though it does contain large amounts of filler (non-coding) DNA sections that prokaryotic DNA does not contain. DNA in eukaryotic cells are, as the name would suggest, found in the nucleus. In prokaryotic cells, DNA is found in the cytoplasm, usually connected in one spot to the plasma membrane. Both cell types possess “extra” DNA. In eukaryotic cells, this extra DNA is found in the mitochondria and chloroplasts. In prokaryotic cells, the extra DNA is found in the form of plasmids, which contain genes that can be activated in emergency situations when needed. Aside from differences in the actual structure of the DNA, there is also a difference in the general amount. Prokaryotes have only a few genes, whereas eukaryotes, though the number of chromosomes varies greatly between species, contain far more genes and thus far more DNA than prokaryotes.
Despite all these important differences between the DNA of prokaryotes and eukaryotes, they are actually quite similar. Both types of DNA share the same base pairs. The same nucleotides. Adenine binds with Thymine, and Guanine binds with cytosine regardless of cell type, this holds true for all DNA. All DNA is held together with phosphodiester bonds between the sugar backbones and base pairs, and hydrogen bonds between the nucleotide bases, binding them together. Along with being made of the same components, DNA in both cell types is arranged in a double helix structure, this is a defining characteristic of all DNA, as is its unique anti-parallel orientation of the DNA strands that are found in both types of cells. Because of this anti-parallel orientation eukaryotes and prokaryotes have in common, the DNA of each cell type is able undergo semi-conservative replication.
As you can see, even the DNA of prokaryotes and eukaryotes reflects the similarities they share, and the differences between them.