Recognize Bacterial

The first bacterium discovered by Anthony van Leeuwenhoek in 1674 using a homemade microscope. The term bacterium was introduced at a later date by Ehrenberg in 1828, taken from the Greek word βακτηριον which means "small stick".

Bacteria, from the Latin word bacterium (plural, bacteria), is the largest group of living organisms. They are very small (microscopic) and mostly unicellular (single celled), with a relatively simple cell structure with no nucleus / nucleus, cytoskeleton, and organelles such as mitochondria and chloroplasts. Their cell structure is described further in the article about prokaryotes, because bacteria are prokaryotes, to distinguish them from organisms that have more complex cells called eukaryotes. The term "bacteria" has been applied to all prokaryotes or to a large group of them, depending on ideas about their relationship.

Bacteria are the most abundant of all organisms. They are spread (being everywhere) in soil, water, and as symbionts of other organisms. Many pathogens are bacteria. Most of them are small, usually measuring only 0.5 to 5 μm, although there are species can reach 0.3 mm in diameter (Thiomargarita). They generally have cell walls, such as plant and fungal cells, but with very different composition (peptidoglycans). Many who move using flagella, which differ in structure from the flagella of other groups.

Bacteria cell structure

As prokaryotes (organisms without nucleus membrane) in general, all bacteria have a relatively simple cell structure. Structure is the most important bacterial cell wall. Bacteria can be classified into two groups: Gram positive and Gram negative based on differences in the structure of the cell dinging. Gram positive bacteria have cell walls composed of thick layers of peptidoglycan and teichoic acid. While Gram-negative bacteria have outer layer, lipopolysaccharide - consists of a membrane and a thin peptidoglycan layer located on periplasma (in between the outer layer and cytoplasmic membrane).

Many bacteria have structures outside the cell such as flagella and fimbria that is used to move, stick and conjugation. Some bacteria also have a capsule or slime layer that helps the bacteria on a surface attachment and biofilm formation. Bacteria also have a chromosome, ribosomes, and several other species have granules of food, gas vacuoles and magnetosom.

Some bacteria can form endospores that enable them to survive in extreme environments