What are Some Structural Characteristics of Bacteria?
Bacteria are the world’s most common organisms, with an estimated five nonillion (5 x 1030) bacteria on Earth. “Bacterium” means “small staff” in Greek. They come in a variety of shapes and sizes — rods, spheres, spirals, helical, blogs, etc. The largest bacteria is half a millimeter long (though this is very atypical), and the smallest is just 0.3 microns across. Typical size is between 0.5 and 5.0 microns. The characteristics of bacteria are among the most varied in any domain of life — the relatedness between two species of bacteria is often much less than the relation between any two given metazoans, say a human and a slug. Though they infect everything and can kill off billions of other organisms, bacteria have a relatively simple structure. Though they were once thought of as simple cytoplasm bags, bacteria do actually have complexity, just not nearly as much as found in eukaryotic (large, complex, nucleated) cells. The basic structure is a capsule protected by a lipid membrane
