VVE: How do they function?

Before we can understand how they function, let's take a look at what they are made out of! Since there are many types of viruses we are going to work with the T-Even Bacteriophage because it has easily recognizable features.

Composition of T-Even Bacteriophage

The Capsid
The Capsid of a virus is basically its "brains." It contains an outter protien coat which is wrapped around a central core of a highly complex chemical called nucleic acid. Typically, the capsid is divided into distinct subunits called capsomeres. X-rays have shown that viruses have an icosahendron capsid (30 sides).

The Body
Viruses have a highly complex symmetry, somewhat like the Surveyor space craft send to explore the moon. Attached to the head (capsid) is a rod like structure that consists of a retractible sheath surrounding a central hallow core.

The Tails
At the very end of the core is a spiked plate carrying 6 slender tail fibers which help anchor the virus to its host.

Nucleic Acid ( DNA / RNA )

What is it?

So what is it that causes viruses to attack other cells and infect them in order to replicate? Well, it all comes down to lifes Master Molecule. The nucleic acid of a virus -- the viral chromosome -- may be either DNA (deoxyribose nucleic acid) or RNA (ribose nucleic acid), single stranded or double stranded, circular or linear. Viral chromosome vary greatly in size, from some 5,400 nucleotides (4 bases A,T,G,C) to 180,000 for the T-Even Bacteriophage.

What does it do?

What the RNA or DNA does is it supplies the codes for building the protien coat (capsid) and for producing certian enzymes needed to replicate more viruses. The codes also provide enzymes that allow the newly built viruses to do something called lyse (or break through the cell). Which in turn totally ruptures the cells outter membrane, thus totally destroying it.

To the left is a piece of DNA. The four nucleotides interlock with each other (T-A & G-C). This interlocking pattern continues throughout the spiral of DNA in different combinations. These sequences of nucleotides are the basic instructions for creating all biological life. Think of it as an instruction manual on how to build special types of proteins, which in turn makes viruses, including us. For a more detialed view of how viruses replicate using DNA/RNA move on to the next section.