Viruses and Bacteria

Viruses and Bacteria

It's easy to mix these up since compared to us, both are VERY SMALL.

But bacteria, given the proper nutrients, can grow and reproduce on their own. Viruses cannot "live" or reproduce without getting inside some living cell, whether it's a plant, animal, or bacteria.

And compared to viruses, bacteria are huge (see HowBig).

The Virus that Infect Bacteria

T4 bacteriophage is a virus that looks like an alien landing pod.

With its six legs, the bacteriophage attaches to the surface of the much larger bacteria Escherichia coli (E. coli).

Once attached, the bacteriophage injects DNA into the bacterium. The DNA instructs the bacterium to produce masses of new viruses.

So many are produced, that the E. coli bursts.

Now THAT's a NASTY virus!

Here's what an actual population of E. coli looks like as it is wiped out by T4 bacteriophage. You can also view this in an 800K time-lapse movie. For more on viruses that infect bacteria, visit the Bacteriophage Ecology Group and see their collection of phage images from around the Web.

Need a longer, larger, silent video of this clip for classroom use? It is available for immediate download as part of the "Bacteria Collection".

sumber : http://www.cellsalive.com/phage.htm