Posts Tagged ‘genetic material’
Overview of Virus (part 1)
1. Introduction
(Latin for ‘poison’) organizational entities composed only of genetic material surrounded by a protective envelope. The term virus was used in the last decade of last century to describe the disease-causing agents smaller than bacteria. Lack of independent living but can replicate inside living cells, often damaging to his guest in this process. The hundreds of known viruses are the cause of many different diseases in humans, animals, bacteria and plants.
The existence of viruses was established in 1892, when Russian scientist Dmitry I. Ivanovsky, found microscopic particles, known later as the snuff mosaic virus. In 1898 the Dutchman botanist Martinus W. Beijerinck called these particles infectious virus. A few years later, viruses were found growing on bacteria, which are called bacteriophages. In 1935, the American biochemist Wendell Meredith Stanley crystallized the snuff mosaic virus, showing that consisted only of genetic material called ribonucleic acid (RNA) and an envelope protein. In the 1940s the development of electron microscopy enabled the visualization of the virus for the first time. Years later, the development of high-speed centrifuges able to concentrate and purify. The study of animal virus reached its peak in the 1950s with the development of cell culture methods, support of viral replication in the laboratory. Then they discovered many viruses, most of which were sampled in the 1960s and 1970s, in order to determine their physical and chemical characteristics. Read the rest of this entry »