Photobucket
Photobucket

HELLO <body><script type="text/javascript"> function setAttributeOnload(object, attribute, val) { if(window.addEventListener) { window.addEventListener('load', function(){ object[attribute] = val; }, false); } else { window.attachEvent('onload', function(){ object[attribute] = val; }); } } </script> <div id="navbar-iframe-container"></div> <script type="text/javascript" src="https://apis.google.com/js/platform.js"></script> <script type="text/javascript"> gapi.load("gapi.iframes:gapi.iframes.style.bubble", function() { if (gapi.iframes && gapi.iframes.getContext) { gapi.iframes.getContext().openChild({ url: 'https://www.blogger.com/navbar/4645296235723893839?origin\x3dhttps://microvirology.blogspot.com', where: document.getElementById("navbar-iframe-container"), id: "navbar-iframe" }); } }); </script>
Tuesday, December 23, 2008

Introduction to Virology
Virology and Its Importance

Virology is a branch of microbiology that studies viruses and diseases caused by them.

The study of viruses is vital as many fatal diseases are caused by viruses such as AIDs, Hepatitis and Dengue Haemorrhagic Fever and are the cause of several epidemics and pandemics that killed large numbers of people such as the recent SARS outbreak. In addition viruses also play an important role in research by being used as vectors of genetic material in the study of genetics. Since viruses posses such important biological roles and can be used as a tool for further technological advancement, hence it is viable and essential that it is studied and researched upon.


Fig 1: Hepatitis B Viron

Fig 2: 1918 Influenza Pandemic



Brief History of Biology

Viruses were not closely studied till 1898 when a Russian Scientist, Martinus Beijernick discovered that the tobacco mosaic disease was caused by a filterable agent smaller than that of viruses. Hence the Tobacco Mosaic Virus became the first known virus to be discovered.

Before the discovery of viruses, methods to combat it were already developed. For instance, in 1885 in Europe Edward Jenner developed the first vaccine which was used to combat the small pox virus. He realized that milkmaids who had cowpox did not contract smallpox at all and realized that cow pox could be used as a vaccine.

The table below shows a rough timeline of the important events of Virology till 1898.

(Click Image to Magnify)

Definition of Viruses

Viruses are described as infectious obligate intracellular parasites possessing the following structural features:

(Click Image to Magnify)

Viruses have different shapes and sizes and can be classified into different categories based on that. The categories are Helical, Icosahedral, Enveloped, and Complex. The picture below shows how a typical virus from the respective categories above looks like.

Fig 3: Helical Virus

Fig 5: Enveloped Virus

Fig 4: Icosahedral Virus
Fig 6: Complex Virus


Videos

These video clips shows how viruses infect cells and how they make use of the host cell’s machinery to replicate.










-------------------------------------------------------------------------------

References:

Pictures:
·Fig1:http://sg.wrs.yahoo.com/_ylt=A0S0zu9OXk9JJC4AOIIu4gt./SIG=12q3mcovb/EXP=1230024654/**http%3A/www.vfa.de/img/db/hepatitis_b_virus_16857295.jpg_175_177_60.jpg
· Fig2: http://pd.ilt.columbia.edu/banneker/fgproj/fgimages/fnsthsp1_s.jpg
· Fig3:http://media-2.web.britannica.com/eb-media/44/4944-004-332E2643.gif
· Fig4: http://www.public-health.uiowa.edu/adv/pics/Adeno1.gif
· Fig5: http://student.ccbcmd.edu/courses/bio141/lecguide/unit3/viruses/images/u2fig2d.jpg
· Fig6: http://www.nsf.gov/od/lpa/news/02/images/bacteriophage.jpg

Videos:
· http://www.youtube.com/watch?v=gU8XeqI7yts&feature=related
· http://www.youtube.com/watch?v=A409yO-G1Mk&feature=related

Information:
· http://www.kcom.edu/faculty/chamberlain/website/lects/PROPERT.HTM#gen
· http://faculty.clintoncc.suny.edu/faculty/michael.gregory/files/bio%20102/bio%20102%20lectures/viruses/viruses.htm




HELLO

12:30 AM