Bacteria: Definition, Structure, Advantages, Varieties, and Uses


Bacteria: Definition, Structure, Advantages, Varieties, and Uses


Bacteria: Definition, Structure, Advantages, Varieties, and Uses; Bacterias are small single-cell organisms. Bacteria are discovering nearly in every single place on Earth and are important to the planet’s ecosystems. The human body is filling with bacteria, particularly within the abdomen and mouth. Most bacteria within the physique are innocent, and a few are even useful. Typically bacteria lend us a serving to hand, resembling by curdling milk into yogurt or serving to with our digestion. Some bacteria have a tail, known as a flagellum. The flagellum helps a bacterium maneuver around.

Bacteria are present in each habitat on Earth: soil, rock, oceans, and even arctic snow. Some stay in or on different organisms including crops and animals including people. There are roughly 10 instances as many bacterial cells as human cells within the human body. Loads of these bacterial cells are discover lining the digestive system. 


Bacterial cells usually surround by two protecting coverings: an outer cell wall and an internal cell membrane. Sure bacteria, just like mycoplasmas, should not have a cell wall in any respect. Some bacteria might also have a third, outermost protecting layer referred to as the capsule. Whip-like extensions usually cowl the surfaces of bacteria — lengthy ones referred to as flagella or quick ones referred to as pili — that assist bacteria to maneuver round and fix to a bunch.

Though bacterial cells are a lot smaller and easier in structure than eukaryotic cells, bacteria are an exceedingly various group of organisms that differ in measurement, form, habitat, and metabolism.

Particular person bacteria can assume one in every of three primary shapes: spherical (coccus), rodlike (bacillus), or curved (vibrio, spirillum, or spirochete).

A median-size bacterium—such because the rod-shaped Escherichia coli, a traditional inhabitant of the intestinal tract of people and animals—is about 2 micrometers (μm; millionths of a meter) lengthy and 0.5 μm in diameter and the spherical cells of Staphylococcus aureus are as much as 1 μm in diameter.

Bacteria are unicellular microorganisms and thus are usually not organizing into tissues. Every bacterium grows and divides independently of some other bacterium, though aggregates of bacteria, generally containing members of various species, are continuously discover. Many bacteria can type aggregated constructions referred to as biofilms.

Advantages of Bacteria

Some bacteria are good for you, together with the bacteria in your digestive system, or intestine. These bacteria assist to interrupt down meals and hold you wholesome. Bacteria are utilizing in meal manufacturing to make yogurt and fermented foods. The ecosystem depends on bacteria to operate correctly. For instance, bacteria break down lifeless matter within the atmosphere, like lifeless leaves, releasing carbon dioxide and vitamins within the course of. Without the discharge of carbon dioxide, crops are unable to develop.


There are numerous several types of bacteria:

  • Spherical: Bacteria form like a ball are referred to as cocci, and a single bacterium is a coccus. Examples embody the streptococcus group, answerable for “strep throat.”
  • Rod-shaped: These are generally known as bacilli (singular bacillus). Some rod-shape bacteria are curve. These are generally known as vibrio. Examples of rod-shaped bacteria embody Bacillus anthracis (B. anthracis), or anthrax.
  • Spiral: These are generally known as spirilla (singular spirillus). If their coil may be very tight they’re generally known as spirochetes. Leptospirosis, Lyme illness, and syphilis are attributable to bacteria of this form.

Makes use of

Bacteria sometimes regard as dangerous, however many are useful. We’d not exist without them. The oxygen we breathe was in all probability create by the exercise of bacteria.

The place do they stay

Bacteria could be present in the soil, water, crops, animals, arctic ice, and glaciers. Aerobes, or cardio bacteria, can solely develop the place there may be oxygen. Some sorts could cause issues for the human atmosphere, resembling corrosion, fouling, issues with water readability, and dangerous smells. Mesophiles, or mesophilic bacteria, are the bacteria answerable for most human infections. They thrive in average temperatures, around 37°C. Deep within the ocean, bacteria stay in complete darkness by thermal vents, the place each temperature and strain are excessive. They make their very own meals by oxidizing sulfur that comes from deep contained in the earth.