BACTERIA: Bacteria are small single-celled organisms.
Discovery: Robert Hook was the first scientist who described the fruiting structure of molds in 1665 and Antoni Van Leeuwenhook was another scientist credited with the discovery of bacteria in 1976. Bacteria are found almost everywhere on Earth. The human body is full of bacteria and is estimated to contain more bacterial cells than human cells. Bacteria are like eukaryotic cells. They have cytoplasm, ribosomes, and a plasma membrane.
Four Common Types: There are four common types of bacteria. These are
⦁ Cocuss Form: These are spherical bacteria
⦁ Bacillus Form: These are rod-shaped bacteria
⦁ Spirillia Form: These are spiral-shaped bacteria that occur singly
⦁ Vibrio Form: These are common-shaped bacteria
Harmful: Not all bacteria are harmful some bacteria that live in your body are helpful. For example, LACTOBACILLUS ACIDOPHILUS (bacteria) is harmful because it resides in your intestine_____ helps you to digest food, destroy some disease-causing organisms, and provides nutrients. There are three notable common traits of bacteria
⦁ Lack of membrane-bound organelle
⦁ Unicellular
⦁ And small (usually microscopic) size Not all prokaryotes are bacteria some are archaic, and although they share common physical features bacteria, are ancestrally different from bacteria.
Following are the Top Ten bacteria:
⦁ Deinococuss radiodurans
⦁ Myxococuss Xanthus
⦁ Vesinia parties
⦁ Escherichia coli
⦁ Salmonella typhimurium
⦁ Epulopiscism _____the big boy of kingdom____ about as large as this full stop
⦁ Pseudomonas syringe
⦁ Carsonella radii
How do bacteria grow?
Like all organisms bacteria also need to grow and multiply to survive as specie. Bacteria divide by binary fission process. When sufficient food is available bacteria multiply quickly by doubling in size and then splitting in half, to create two new cells when the cell divides this creates two new cells that are the same sick.
Diseases:
By bacteria, there are major diseases that occur include: cholera, diphtheria, bacterial meningitis, tetanus, Lyme disease Gonorrhea, and syphilis.
Tuberculosis (TB) is caused by bacteria called mycobacterium tuberculosis. These bacteria usually attack the lungs, but the bacteria can attack any part of the body such as the kidney, spine, and brain. Not everyone infected with TB bacteria becomes sick.
Alive or not: Bacteria are alive. Although it is a single cell, it can generate energy and the molecules needed to sustain itself and it can reproduce.
Structure: a bacterial cell consists of a variety of components. Some of these are external and the others are internal to the cell wall. The external components include capsule and slime layers flagella and pili. Some structures are present only in certain specie.
Many bacteria secrete sticky substances that form protective layers called capsules outside the wall. In some cases, this layer is diffuse and known as the slime layer. Most bacterial capsules are composed of polysaccharides while a few capsules are polypeptides. The glue-like nature of the capsule helps bacteria to adhere to their substrate or unite to form colonies. The capsule provides increased resistance to disease-causing bacteria against antibodies.
Most bacteria are motile and the organs of locomotion are hair-like, helical cytoplasmic appendages, the flagella. The flagella may be present at one or both ends of the bacterial cell. In some cases, they appear alongside the sides or all around the bacterium.
The motile, as well as non-motile species, possess hollow, filamentous rods called pili or fimbriae. These are composed of a protein pill. These are concerned with cell-to-cell attachment. The F pilus or pilus, are involved in bacterial mating during reproduction.
The cell wall is present beneath the capsule and external to the cytoplasmic membrane. It is a rigid structure that gives shape to the cell. The cell wall is necessary for bacterial growth and development. The cells whose cell walls have been completely removed are incapable of normal growth and division.
The cell material bounded by the cytoplasmic membrane is cytoplasm. It can be differentiated into a liquid part called cytosol, an area in which nuclear material is concentrated, and a portion rich in ribosomes.
In the bacterial cell, cytosol provides a chemical environment for metabolic and cellular activities. The cytosol is a complex concentrated solution of inorganic acids, amino acids, proteins, peptides, nitrogenous bases, vitamins, enzymes, and coenzymes.
The bacterial chromosome consists of DNA molecules formed of about 5(106) base pairs and about 1mm in length. Very little protein is associated with it. The bacterial chromosome is primitive and usually referred to as nucleoid.
In most bacteria, the DNA is concentrated as a mass of fibers, and the region of the cytoplasm containing it stains less than the surrounding cytoplasm. It is called the nucleoid region of the nuclear body. In Escherichia coli, the bacterial chromosome is in the form of a ring of a double-stranded DNA molecule.
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