Bacteria
4. Bacteria
Structure
Bacteria are microorganisms that lack a nucleus and have a cell wall composed of peptidoglycan, a protein-sugar molecule. Bacteria are the most common organisms on earth and are intimately connected to the lives of all organisms. The common structural forms are
Bacteria are microorganisms that lack a nucleus and have a cell wall composed of peptidoglycan, a protein-sugar molecule. Bacteria are the most common organisms on earth and are intimately connected to the lives of all organisms. The common structural forms are
- Spherical or ovoid (coccus )
- rod shaped or cylindrical (bacillus )
- spiral or screw (spirillum) Many forms of bacteria are not capable of independent movement,. Some Bacteria which live in liquid often have thread like projections called flagella (e.g Salmonella bacterium)
Reproduction
Reproduction in bacteria is largely by binary fission i.e. it splits into two. In some case due to some extreme environmental conditions, they
form tiny structures is called Spores. It is formed by condensation of protoplasm into a spherical or egg shaped body and they germinate under favourable conditions. Some bacteria exhibit a type of sexual reproduction.
form tiny structures is called Spores. It is formed by condensation of protoplasm into a spherical or egg shaped body and they germinate under favourable conditions. Some bacteria exhibit a type of sexual reproduction.
Human Diseases caused by bacteria
Disease
|
Name of Bacteria
|
Mode of Transmission
|
Septic sore throat
|
Streptococccus
|
By direct contact & droplets
|
Diptheria
|
Corynebacterim diptheriae
|
Infect respiratory tract by carrier, direct contact, droplets and food
|
Pneumonia
|
Diplococcus pneumoniae
|
respiratory tract,lungs by direct contact, droplets and food.
|
Tuberculosis
|
Mycobacterium
|
Lungs, bones etc by direct contact
|
Plague or Babonic Plague
|
Yersinia pestis
|
Rat flea spreads from rat to man
|
Tetanus
|
Clostridium tetani
|
Bacteria in soil, enter through wounds
|
Typhoid
|
Samonella typhi
|
Flies, food, faeces, water and carriers
|
Typhoid
|
Samonella typhi
|
Flies, food, faeces, water and carriers
|
Cholera
|
Vibrio Cholerae
|
Flies, food, faeces, water and carriers
|
Bacillary dysentery
|
Shigella dysenteriae
|
Flies, food, faeces, water and carriers
|
Whooping Cough
|
Hemophilus pertussis
|
Droplets
|
Gonorrhoea
|
Neisseria gomorrhoeae
|
Sexual intercourse
|
Syphilis
|
Treponema Pallidum
|
Sexual intercourse
|
Leprosy
|
Mycobacterium leprae
|
Sexual intercourse
|
Leprosy
|
Mycobacterium leprae
|
Long and close contact with infected
|
Botulism
|
Clostridium botulinum
|
Organism produces poison in food
|
Treatment
Vaccination or Immunization or inoculation is a method of stimulating resistance in the human body to specific diseases using microorganisms -bacteria or viruses-that have been modified or killed. These vaccines do not cause diseases but stimulates the production of antibodies in its blood. It build a defense mechanism that continuously guards against the disease. If a person immunized against a particular disease later comes into contact with the disease-causing agent, the immune system is immediately able to respond defensively. Bacterial vaccines are used chiefly in immunizing human beings and animals against such diseases on diphtheria, cholera and typhoid fever.
Uses
Aerobic bacteria uses oxygen for respiration and anaerobic bacteria maintain respiration without free oxygen and this process is known as fermentation. So it is used in the production of vinegar and other substances. Some bacteria decompose organic matter and fix nitrogen by converting atmospheric nitrogen into nitrates. These are mainly found in the roots of legumes such as peas, clover and alfalfa. In human beings, intestinal bacteria produce lactic acid which promotes digestion.
Bioremediation: It is the use of microorganisms such as bacteria to remove environmental pollutants from soil, water or gases.
Serum
Serum is a preparation from blood of an animal that has been inoculated with bacteria. This contains antibodies that formed as a consequence of the disease. The important antibodies produced with the help of bacteria are streptomycin, Aureomycin, Terramycin. Please note that penicillin is produced by an Fungi .
Important scientists who studied bacteria
- Antoni van Leeuwenhoek : The first person to systematically study bacteria.
- Louis Pasteur: Showed that microbes do not arise from nonliving matter (germ theory). He also founded the science of microbiology, invented the process of pasteurization, and developed vaccines for several diseases, including rabies.
- Robert Koch: showed that bacteria could cause disease.
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