Saturday, 28 September 2013

Properties of Bacteria


  • These are microscopic single-celled organisms.
  • The three basic shapes of these are: spheres, rods and spirals.

Features of bacteria:
  • They have no real nucleus but contain a single circular chromosome.
  • They also have a plasmid which is a small singular ring of DNA that can contain genes for antibiotic resistance. Can be used in genetic engineering as vectors.
  • Have a cell membrane and cell wall (made of carbohydrates and proteins).
  • A slime capsule.
  • Some have a flagellum or flagella to move.
  • Reproduce asexually by binary fission every 20 minutes.
  • They obtain nutrition mainly by feeding off other living or dead organisms, but many bacteria are important autotrophs, which carry out photosynthesis.
  • There are useful bacteria to humans such as lactobacillus bulgaricus used in making yoghurt from milk
  • Others are pathogens such as Pneumococcus which causes pneumonia.