3. Contents
SRL # Topic
1 Introduction (with a picture of Bacteria)
2 Comparision of the size of Bacteria with other organisms
3 Key concept of Bacteria
4 Structure of Bacteria
5 Identification of Bacteria on the basis of shape
6 Mode of reproduction of the Bacteria
7 Nutrition and growth
8 Speciality of Bacteria
9 Identification of Bacteria
10 Bacterial Cell wall
11 Hazards of Bcteria
12 Beneficts of bacteria
13 Conclusion
14 Bibliography
7. Key Concepts about Bacteria
Kingdom Monera
Prokaryote=no nucleus or internal
compartments
All are single cells
Single circular piece of DNA
8. Structure of Bacteria
Structure Function
Cell Wall Protects and gives shape
Outer
Membrane
Protects against antibodies
Cell
Membrane
Regulates movement of
materials, contains enzymes
important to cellular
respiration
Cytoplasm Contains DNA, ribosomes,
essential compounds
Chromosome Carries genetic information.
It is circular
9. Structure of Bacteria
Plasmid Contains some genes
obtained through
recombination
Capsule
& Slime
Layer
Protects the cell and
assist in attaching cell to
other surfaces
Endospo
re
Protects cell against harsh
environments
Pilus Assists the cell in
attaching to other
surfaces
Flagellu
m
Moves the cell
10. Shapes- How bacteria are
identified!
Bacilli- rod shaped
Spirilla- spiral shaped
Cocci- sphere shaped
Staphylococci- grape-like clusters
Streptococci- in chains
18. Nutrition and Growth
Autotroph- producer, makes energy from
environmental sources
Chemoautotrophs- Take Hydrogen from NH3 or
H2S and oxidize it using the energy to make amino
acids and proteins
Photoautotrophs- photosynthetic- Uses sunlight
for energy
19. Nutrition and Growth
Heterotroph- feed on organic material formed
by other organisms
Decomposers
Secrete enzymes in their organic environment
and then absorb the nutrients
They can metabolize their host
20. Endospores
Some bacteria can form endospores, which
are non-replicative cell forms that are highly
resistant to environmental factors.
Endospore
21. Gram Stain- Another way to
identify Bacteria
Purple= Gram Positive Pink= Gram Negative
22. Bacterial Cell Walls
•Peptidoglycan is the material that makes up bacterial cell walls
Thicker peptidoglycan
layer but not outer
membrane means gram +
Thinner peptidoglycan layer
with an outer membrane
means gram -
23. How do Bacteria cause
disease?
Metabolize their host for food (Heterotrophic
bacteria)
Secrete a toxin which can attack other body
parts (Botulism is an example)
Contain an endotoxin in their cell wall which
is released when the bacterium dies. An
example of this is salmonella.
24. How can Bacteria work to our
benefit?
Digest waste at sewage plants
Chemical industry- make acetone and
butanol
Pharmaceutical- vitamins, antibiotics, insulin
Food- yogurt, cheese, alcoholic beverages
Decomposer
Nitrogen fixers
Symbiosis
25. Conclusion
Through this project I came to know a lot
about Bacteria its characteristic features and
also how to identify it. This project was a
great help to me as this information might
help me in my future.