A Basic Guide to Bacteria

Bacteria are a type of microorganism. They are unicellular, meaning they are single celled. They are, overall, relatively simple organisms.

Bacteria are a type of prokaryote. A prokaryote is a type of cell that lacks a nucleus, meaning that the genetic material of a bacterial cell is not confined within a special membrane. They also lack various other organelles such as mitochondria. Instead of a nucleus, bacterial cells often have a region called the nucleoid which is where the genetic material is housed despite the lack of the nuclear membrane.

The cell walls of bacteria are composed primarily of peptidoglycan, sometimes also called murein. This is a type of carbohydrate and protein complex. This is one way in which bacteria is set apart from archaea, another type of prokaryote and domain of classification, since the cell walls of archaea, if at all present, lack this complex. Many types of bacteria depend on the integrity of the cell wall for their survival.

Individual bacteria may form groupings, such as pairs, cluster, or chains. Often the formation is a characteristic of a particular species of bacteria. The cells also usually appear in one of several shapes. Among the most common of these shapes are a rod like shape known as bacillus, coccus which is an ovoid shape, and spiral which is, as it sounds, curved or perhaps corkscrew shaped.

Generally, bacteria reproduce by binary fission orprokaryotic fission. This is the form of asexual reproduction used by all prokaryotic organisms and is the process of a cell dividing itself into two equal and identical cells.

Some bacteria are able to propel themselves thanks to rigid protein structures along the outer edges of the cell called flagella. The flagella can be arranged in four different ways. An arrangement of a single polar flagellum is called monotrichous. Flagella at each end of the cell is amphitrichous. Multiple flagella located at one particular place is lophotrichous and peritrichous is an arrangement of flagella all over the cell. The cells can change the direction and even speed of these flagella.

Some bacteria can derive nutrition from inorganic substances or photosynthesis, but mostly bacteria use organic chemicals for nutrition. These chemicals can be derived from either dead or living organisms.