Gene Knockout Methodology and Insulin Action - Essay Example

Gene knockout methodology is achieved using various techniques. The process commences with a plasmid in a test tube, a DNA structure or bacterial chromosome then progressing to cell culture. Genetic transformation of the individual cells takes place with the DNA structure or construct. In this process, the cells are introduced with the DNA and combined with a stem cell. The target gene and DNA construct are engineered to combine with each other. This is done by fusing the DNA construct with the gene sequences resulting in the recombination of the gene sequence.

Consequently an interruption within the gene occurs and often will result into a non-functional protein. For most DNA constructs and cell, recombination occurs very rarely and therefore the substance selected for interrupting the gene sequence is a reporter gene. This gene is used to discover if the gene under consideration has functional expression in cell regeneration or function. Insulin plays an important role in metabolism, particularly in lipid and carbohydrate metabolism. Protein and mineral metabolism are also influenced by the action of Insulin.

Inconsequence, the order and functioning of insulin has profound effects on tissues and organs (EDES 2007). The insulin receptor, similar to protein hormone receptors, is rooted within the plasma membrane. Two alpha subunits comprise the insulin receptor and also by two beta subunits which are connected by disulfide bonds. The alpha subunits are located outside the cells and hold insulin binding domains. The beta subunits on the other hand permeate the plasma membrane. As a tyrosine kinase, the insulin receptor acts as an enzyme that transmits phosphate groups from ATP to intracellular target proteins that contain tyrosine remnants.

When the insulin binds to the alpha subunits, the beta subunits undergo autophosphorylation - which is the addition of a phosphate group to a protein or small molecule - and initiate the receptor's catalytic process. The insulin receptor further adds phosphate groups to other proteins within cells, resulting in creating a biological reaction. Among the many intracellular proteins, there are several which are phosphorylation substrates for insulin receptors. One such insulin receptor substrate is insulin receptor substrate 1 (IRS-1).

When the process of phosphorylation activates this substrate a number of outcomes occur. IRS-1 functions as a central region for enzyme activation and for producing the effects of insulin. Insulin also effects carbohydrate metabolism. In the small intestines, hydrolysis of dietary carbohydrates like sucrose and starch causes the release of glucose which passes into the blood stream. High concentrations of glucose trigger insulin release which acts on all cells to prepare for glucose storage.

The metabolism of glucose as a result of insulin action depends on the target tissue. Another known effect of insulin is to lessen glucose concentration in blood and when this concentration falls, insulin secretion stops. When insulin is absent, most cells fail to uptake glucose and turn to using alternate sources of energy like fatty acids. Also glycogen synthesis ceases in the liver and there is an