Quotation

LAHORE COLLEGE FOR WOMEN UNIVERSITY

                BS HONS (I)
                SEMESTER II
                MAJOR: CHEMISTRY
                SUBJECT: BOTANY

ASSIGNMENT TOPIC

      STRUCTURAL COMPONENTS OF BACTERIA

SUBMITTED TO

DR. KHAJISTA

SUBMITTED FROM

BEENISH KANWAL:       1368
MALEEHA NASIR:         1371
KOMAL ASHRAF:           1378
RAHAT NOREEN:           1405
ANUM BARKAT:             1427
KANWAL KHALID:         1430

BACTERIA

DEFINITION:
Bacteria are microscopic unicellular prokaryotic organisms characterized by the lack of a membrane-bound nucleus and membrane-bound organelles.

DISCOVERY:
Bacteria were first observed by Antonie van Leeuwenhoek in
1676, using a single-lens microscope of his own design. He called them "animalcules".
Louis Pasteur demonstrated in 1859 that the fermentation process is caused by the growth of microorganisms, and that this growth is not due to spontaneous generation. Pasteur was an early advocate of the germ theory of disease.
Though it was known in the nineteenth century that bacteria are the cause of many diseases, no effective antibacterial treatments were available. In 1910, Paul Ehrlich developed the first antibiotic and was awarded Nobel Prize in 1908.

ORIGION AND EARLY EVOLUTION:
The ancestors of modern bacteria were single-celled microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. Bacteria were also involved in the second great evolutionary divergence, that of the archaea and eukaryotes.
MORPHOLOGY:
Bacteria display a wide diversity of shapes and sizes, called morphologies.
      SIZE:
      Bacterial cells are about one tenth the sizes of eukaryotic cells and are typically 0.5–5.0 micrometers in length. However, a few species–for example Thiomargarita namibiensis and Epulopiscium fishelsoni–are up to half a millimeter long and are visible to the unaided eye. Among the smallest bacteria are members of the genus Mycoplasma, which...