Bacteria

Bacteria is a simple organism that consist of one cell. They are among the smallest living thing on earth. Most bacteria measures from about 0.3 to 2.0 microns in diameter, and can only be seen through a microscope. Scientist classify bacteria according to shape. Cocci are round and sometimes linked together. Bacilli look like rods, and Vibrios resembles bent rods. There are two types of spiral-shaped bacteria, spirochetes and spirilla.

Bacteria exist almost anywhere you can think of. There are thousands of types of bacteria, most of which are completely harmless to the human body. Some species cause diseases while others are harmless.

The Pros & Cons of Bacteria

Certain kinds of bacteria live in the intestines of human beings and animals. These forms of bacteria are essential in the digestion process. They help the digestion process by eliminating and destroying harmful organisms. Intestinal bacteria also produces some vitamins needed by body.

Bacteria cells resemble the cells of other living things in many ways, and so scientist study bacteria to learn more about complex organisms. For exmaple, the study of bacteria has helped researchers understand how certain characteristics are transferred through heredity. Most species of bacteria reproduce quickly. This enables many scientist to grow large quantities of research due to rapid reproduction of bacteria.

Some kinds of bacteria cause diseases to human beings, animals and plants. The diseases include: cholera, gonnorhea, leporasy, gangrene, pneumonia, tuberculosis, tracheal bronchitis, syphilis, and typhoid fever. Bacteria enters the body through natural openings, such as the nose, mouth, and even breaks or cracks in the skin. In addition to transfer of bacteria through natural openings, bacteria is also transfered from one person to another by means of food, water, and air. Harmful bacteria prevents the body from functioning properly by destroying healthy cells.

Certain bacteria produces posions which cause such diseases such as diperthia, tetanus, and scarlet fever. Some posions are produced by living bacteria while others are released only after bacterium dies. A form of food posioning called botulism is caused by posions from bacteria in improperly canned foods.

Bacteria that may live harmlessly in the body can also cause infections. The infections are only minor compared to posion produceing bacteria. An example of this would include, if bacteria in the throat of a person with low immunity, reproduces faster than the persons body can dispose of them , the result is an infection which is known as sore throat.

As stated earlier, bacteria also causes diseases in animals as well as plants. Athrimax is a bacterial disease that infects many animals, espically cattle and sheep. Plant diseases caused by bacteria include fire blight, which occurs mainly in apple and pear trees, and soft rot, which decays some fruits and vegetables. Bacteria also causes growths called crown galls, which attack various plants.

Protect Yourself From Those Infetious Microbes!

Many bacteria live on the skin , in the mouth, in the intestines, and even in our breathing passages. But the rest of the body tissues are normally free of bacteria. The skin, and the membranes that line the digestive and respitory systems, prevent most harmful bacteria from entering the body. When harmful bacteria does enter the body, white blood cells surround and attack the bacteria. In addition to the white blood cells our blood produces antibodies to fight against infection too. Toxins are neutralized by certain antibodies called antitoxons. Sometimes the body cannot make its own antitoxins fast enough. In such cases, a physician may inject an antitoxin from an animal, such as a horse or rabbit into you to supplement the defiecency of your body to produce antitoxins.

Dead or weakened bacteria are used in making drugs called vaccines, which can prevent the diseases caused by those species of bacteria. Vaccines are injected into the body, to cause the blood to produce antibodies to fight bacteria. Some vaccines protect the body from several years or longer. Drugs called antibioticts are made from microorganisms that inhabit the air, soil, and water. Antibiotics can kill or weaken disease causing bacteria. However, excess use of antibiotics may encourage the spread of bacteria resisitant to the drugs. The drugs then becomes ineffective.

People use chemicals called antiseptcs to prevent bacteria from growing on living tissues such as our skin. Other chemicals, such as disenfectants, are used to destroy bacteria in water and on such items of clothing and utensils. Bacteria can also be killed by heat; thus heat is used to sterilize food and utensils.

The Structure of Bacteria

Nearly all kinds of bacteria are enclosed by a tough protective layer called the cell wall. The cell wall gives the bacterium its shape and enables it to live in a wide variety of enviroments. Some species are further enclosed by a capsule, a slimy layer outside the cell wall. The capsule makes the cell refraned from decstructive chemicals. All bacteria have a cell membrane, an elastic, baglike structure just inside the cell wall. Small molecules of food enter the cell through pores in the membrane, but large molecules can't pass through. Inside the membrane consist cytoplasm, a soft, jellylike substance. The cytoplasm contains chemicals called enzymes; which help break down food and build cell parts.

Like living cells bacteria contain DNA.. DNA controls the cells reproduction, growth, and all other activities. The DNA of bacterial cell forms an area of the cytoplasm called the nucleoid. In all other organisms except blue green alage, the DNA, is the nucleus, a part of the cell seperated from the cytoplasm by a membrane.

The Wonderful Life of Bacteria

Bacteria lives almost anywhere you can think of, even in places where other forms of life cannot prevail. The air, water, and upper layers of soil contain many bacteria. Bacteria are always present in the digestive and respiratory systems and on the skin of both human beings and animals.

Certain bacteria, called aerobes, require oxygen to live, but others known as anaerobes, can survive without it. Some anaerobes can exist with or without oxygen. Other anaerobes cannot live with even a trace of oxygen in their enviroment.

Some bacteria protect themeselves against lack of food, water, or air, by forming a new, and thicker cell membrane inside its old one. The cell material surrounding the new one dies. The remaining organism becomes inactive and is called a bacterial spore. Bacterial spores can live for decades or even longer because they can resist extremely high or low temeratures and harsh conditions. If food, water, and air become available to the spore, it changes itself back to active bacteria.

Bacteria is carried long distances by air and water currents. Clothing, utensils, and other objects also carry bacteria. Various kinds of bacteria have thin hairs that enable them to swim. Some species that lack these thin hairsmove about wriggling.

Most kinds of bacteria called heterotrophic baacteria, feed on other organisms. Some kinds of bacteria known as autotrophic bacteria, manufacture their own food. Which is clearly the opposite of heterotrophic bacterica. For example plant bacteria makes it's own food, from carbon dioxide, water, and sunlight. Certain bacteria may be autotrophic or heterotrophic depending on food availability. The majority of heterotrophic bacteria feed on dead organisms. Others are parasites. Some parasitic bacteria cause little or no harm to the host organism, but others can cause diseases.

Most bacteria reproduce assexually, each cell simply divides into two identical cells by a process called binary fission. Most bacteria reproduce quickly, and some species double their number every 20 minutes. If one of these cells were given enough food, over a billion bacteria would be produced in 10 hours. Industrial and labratory processes often produce enormous amounts of bacteria. But in nature, bacteria lack an adequate food supply to maintain such a high rate of reproduction.