Molecular Biology

Molecular biology uses a set of techniques used to manipulate biological systems on a molecular level, including the manipulation of DNA or genes. DNA contains the blueprint of all biological activities in an organism. DNA is contained within the genome and is divided up into thousands of genes; this is where the exact information is coded to make specific proteins. All proteins are built from a pool of twenty amino acids, and require not only the right number of amino acids but also the correct order and conformation.

Table - Amino Acids Glycine Alanine Valine Leucine Isoleucine Serine Threonine Phenylalanine Tyrosine Tryptophan Aspartate Glutamate Asparagine Glutamine Cysteine Methionine Lysine Arginine Histidine Proline

A gene can be thought of as being similar to a train: all trains have engines that steer the train in the right direction, and all trains have cabooses to signal the end of the train. Like trains, genes must have all the correct elements to function properly; they must have the right "engine," the promoter, and "caboose" the termination sequence. These sequences ensure that the gene not only produces the correct protein, but also is turned on, or "expressed", in the right quantity at the right time in the right tissue. For example, Nexia uses a "milk specific" promoter which directs the expression of Protexia™, only in the mammary gland during lactation.

Molecular biologists have found ways of manipulating genes for a variety of purposes. Recombinant DNA technology is the ability to recombine a gene from one organism with another. With specialized enzymes, molecular biologists can cut out genes from their natural genetic environment and insert them into other sequences. Once the gene is in this new environment, called a genetic construct, it can be transferred into an organism of interest.

Using these techniques, molecular biologists can determine how specific genes function, which regions of the genes perform specific functions, and when genes are expressed. For example, gene therapy is a technique that uses molecular biology to replace a faulty gene. In this case, a patient is discovered to have a protein that does not perform its intended function. Using molecular biology, a new gene, which produces the appropriate functional protein, can be introduced into the patient. Nexia employs molecular biologists to produce the genetic constructs that function within goats to make proteins such as Protexia™. (See Overview of Nexia's Process: Molecular Biology)

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