The virus has landed
This is a virus called a T4 bacteriophage
. It has landed on a bacterium. Now it's getting ready to lower its tail, puncture the bacterium's cell wall, and inject its DNA.
When this happens:
1. It immediately stops the bacterium's own genes from being expressed.
2. In 5 minutes, its DNA starts synthesizing enzymes needed to make new copies of the virus.
3. In 10 minutes, its DNA starts replicating.
4. In 12 minutes, new copies of the virus start being formed.
5. In 30 minutes, the bacterium bursts, releasing 100 to 150 new copies of the virus!
This deadly machine is only 0.2 micrometers tall. Its DNA - the instruction book that makes everything work - is contained in the head, which is shaped like an icosahedron. The DNA is 169,000 base pairs long, and it codes for 289 proteins. Biologists understand it quite well now.https://en.wikipedia.org/wiki/Enterobacteria_phage_T4
This picture is not a photograph; it was made by Mike Smith for a company called Xvivo Scientific Animation. You can see other pictures by them here:http://www.xvivo.net/wallpaper/