The present section shall encompass briefly the major cellular structures usually encountered in
the bacteria. Nevertheless, the various functional anatomy of these cell types would throw an ample
light upon the various special activities that such cells perform normally.
The cellular structure should essentially provide the following
three
(
a) a specific container to support the internal contents and to segregate it totally from the external
medium,
(
b) to store and replicate the genetic information, and
(
c) to synthesize energy and other necessary cellular components for the replication of the cell.
In general, the bacterial cells grossly fulfil these requirements completely ; besides, they have
distinguishable characteristic features to help differentiation one from the other.
It is, however, pertinent to state here that extensive hurdles and difficulties were encountered by
the microbiologists across the globe in carrying out the detailed
cytological studies** of bacteria on
account of the following vital factors, such as :
(
i) the extremely small size (dimension) of the microorganism, and
(
ii) almost optically homogeneous nature of the cytoplasm.
As to date, the advent of the development of complex and precisely selective staining techniques
amalgamated with the magnificent discovery of
electron microscope and phase-contrast microscope
have contributed enormously in obtaining a far better in-depth knowledge and understanding of the
‘internal structures of bacterial cells’.
The various important aspects referring to the domain of the
‘bacterial cells’ shall be adequatelydealt with under the following heads stated as under :
(
i) Typical bacterial cell
(
ii) Capsules and slimes
(
iii) Flagella and fimbria
(
iv) Cell envelope(v) Gram-positive and gram-negative bacteria
(
vi) Significance of teichoic acids
(
vii) The cell membrane
(
viii) Bacterial cytoplasm
(
ix) Ribosomes, and(x) Cellular reserve materials