Bacteria

Bacteria, Latinbacterium word (plural, bacteria), is a giant group of living organisms. They are very small (microscopic) and most uniselular (single-celled), with the structure of relatively simple cells without a nucleus / nucleus of the cell, cytoskeleton, and organelles such as mitochondria and chloroplasts. Their cell structure is described in more detail in an article about prokaryotes, because bacteria are prokaryotes, to distinguish them with 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 spread (being everywhere) in the soil, water, and as a symbiosis of other organisms. Many patogenmerupakan bacteria. Most of them small, usually only the size of 0,5-5 μm, although there are species can reach 0.3 mm in diameter (Thiomargarita). They generally have cell walls, such as mushrooms hewandan cells, but with very different composition (peptidoglycan). Many are moved using flagella, which differs in structure from the flagella of other groups.