The Double Helix

This was a reasonably interesting book... Yeah, 'nuff said... For this paper, I received a 25/ 25! The assignment was as follows:

Assignment:

1)Complete the reading assignment for the book The Double Helix: Introduction, Chapters 7-13, 20-end.

2)Consider the supporting questions:

1.Specifically, how is the triplet code in the DNA molecule related to the amino acid sequence in proteins?

2.What are the implications of random changes in the DNA triplet code?

3)Your task is to write a two-page, double-spaced, typed essay addressing the question:

How is the expression of genetic information related to the structure of the DNA molecule?

The Double Helix

“My pulse began to race” says James D. Watson, reflecting on the process of discovering the structure of DNA (The Double Helix, 186). There was a great deal of time, effort, and competition involved in the discovery of the structure of DNA, and for good reason. The leaps and bounds that science has made since this and sequential discoveries have been fascinating and exciting! DNA is what makes up who we are physically, this information is contained in our genes. The expression of genetic information is related to the structure of the DNA molecule.

DNA contains the information necessary for organisms to create protiens. Dictionary.com defines proteins as:

“any of numerous, highly varied organic molecules constituting a large portion of the mass of every life form and necessary in the diet of all animals and other nonphotosynthesizing organisms, composed of 20 or more amino acids linked in a genetically controlled linear sequence into one or more long polypeptide chains, the final shape and other properties of each protein being determined by the side chains of the amino acids and their chemical attachments...”

Dr. Watson, in “The Double Helix,” tells us that “DNA [is] the template upon which RNA chains [are] made. In turn, RNA chains [are]... the templates for protein synthesis.” This gives enormous weight to the importance of DNA in who we are physically.

Contained in our DNA is the code for our genes, which is the code for the proteins that are synthesized (Watson, 74). Proteins are made up of a very specific arrangement of very specific amino acids. This arrangement design is contained in the DNA in a code of triplets (made up by either a purine or pyrimidine nitrogen base as a part of the DNA nucleotide). If the amino acids are not properly ordered, the result will be a useless protein, incapable of performing the function for which it was initially created (On Protein Synthesis, Francis Crick, 158-160).

With this in mind, consider the implications of even one the DNA triplets code being. This would cause the wrong amino acid to be linked to the protein, making a change in the protein, which would result in a useless protein. The DNA code of triplets is what makes up our genes, which is what is copied ultimately resulting in the proteins that make up every aspect of our bodies. Thus, this code of triplets is extremely crucial to life.

The expression of genetic information is more than simply related to the structure of the DNA molecule. It is contained within the structure of the DNA molecule. According to the organization of the DNA molecules, the genes are arranged to call for the proper amino acids, to produce the correct protein. If it seems like this point has been pounded over and over again, it is simply a result of the obvious interconnection and dependence genes have upon the structure of DNA. This is only obvious, however, because of “the evidence that genes [are] made of DNA” (74) which evidence is available to us because of the painstaking years scientists like Dr. Watson spent on these discoveries.

Francis Crick, On Protein Synthesis, http://profiles.nlm.nih.gov/SC/B/B/Z/Y/_/scbbzy.pdf