Bacterias

This is the name that the unicellular organisms that don’t have nucleus and reproduce themselves with a simple cellular division receive.

Electron microscope image of Escherischia coli,

a bacteria thet lives in our intestine

Bacteria are very very small between 1 and 10 micrometers of length and they are very variable on the way they obtain the energy and the food.
Bacteria are all around us, they are in the air, in water; we can classify bacteria depending on shape, way of feeding, if they do the respiration or not....

Not all the bacteria have the capacity of movement but the one that have this capacity they move because they have a flagellum. Flagellum can be located in one of the extreme of the bacteria or all around its surface.

Depending on the direction that the flagellum moves, bacteria can move forward or waving to a fixed direction. Flagellum moves with a rotation movement and doing the movement of a snake.

If we look at bacteria from the outside to the interior we can find:
the capsule, cell wall, membrane, pilus, flagellum, cytoplasm, ribosomes, mesosomes, plasmids, and the DNA without nucleus, REMEMBER!!.

Inner structure of a bacteria

Some useful links to study bacterias:

• http://www.ucmp.berkeley.edu/bacteria/bacteria.html
• http://www.microbeworld.org/