Sunday, 18 March 2012

Genetic Engineering and Insulin Synthesis


Genetically Engineering Insulin             -Corey Rhys-Jones (42903848)

Genetic Engineering is a term used to refer to the application of modern Biotechnology to change the genetic structure of an organism. The genetic structure of an organism may be changed/modified for a number of reasons; ranging from higher crop yield in plants to helping cure complex diseases in humans. Through Recombinant DNA Technology genetic engineering can be employed to treat Diabetes in humans by increasing insulin production.


The fundamental trait symptomatic of Diabetes is elevated ‘blood sugar’ levels. In diabetic patients elevated blood sugar levels are a result of impaired insulin production. Insulin and Glucagon are two hormones produced in the pancreas and are employed to regulate blood sugar levels in the body. Glucagon is released by the pancreas when blood sugar levels fall too low, glucagon releases glucose into the bloodstream resulting in a spike in blood sugar. The function of insulin in the human body is to inhibit the use of glucagon and enable cells to absorb glucose from the blood stream. As a result impaired insulin production directly results in elevated blood sugar (glucose) levels.
 A persistently high blood sugar is referred to as hyperglycaemia which can result in severe organ damage. Diabetes or (Diabetes mellitus) is characterized by persistent hyperglycemia.




To combat this research was launched into synthesising Humulin (an ‘insulin’ that is chemically identical to the one naturally produced in humans). In order to synthesise this researchers inserted the insulin gene into an E. coli bacteria cell through a process termed recombinant DNA technology. The process of humulin synthesis is as follows;


A plasmid is a small circle of bacterial DNA that is independent of the main bacterial chromosome (http://www.thefreedictionary.com/plasmid)

1. A Plasmid is removed from the E. coli cell
2. The plasmid is then opened (cut) by a specialized enzyme
3. The 'gene' or DNA coding for insulin is inserted into the open plasmid
4. The plasmid is then sealed with a specialized enzyme
5. The engineered plasmid is then inserted back into the new E.coli cell
6. The cell then divides by mitosis producing insulin.

The Insulin ‘Gene’

All the genetic code needed to dictate cellular functions (genotypes/phenotypes) is contained within a complex molecule called Deoxyribonucleic Acid (DNA). The structure of DNA is a double helix constructed from a chain of nucleotides; the nucleotides contain a sugar deoxyribose, a phosphate and a nitrogen base. The order of the four different nitrogen bases (adenine, thymine, guanine and cytosine) determines how proteins (like insulin) are synthesised. An inability to produce enough (or any) insulin could be a result of a detrimental mutation changing the order of these nitrogen bases.





To conclude, genetic engineering and recombinant DNA technology can be utilized across a wide scientific field. Through the application of recombinant DNA technology we can treat complex diseases such as diabetes (Diabetes mellitus). Diabetes is treated through regular injections of insulin or its chemical equivalent ‘humulin’.  In order to synthesise this researchers inserted the insulin gene into an E. coli bacteria cell (recombinant DNA technology). Recombinant DNA technology is often employed as a result of incorrect pancreatic function, which can be a result of cellular mutation incorrectly ordering the nitrogen base-pairs which make up DNA. 



1 comment:

  1. The major use for genetic testing is in the area of health and medicine. It has a wide range of applications in this field and patients seeing the results of this use for genetic testing are very thankful for the information they have received.

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