Functional Anatomy of Bacteria- Microbiology|ICDS Supervisor Kerala PSC
Functional Anatomy of Bacteria:
Brief functions:
#1 Cell Wall:
acts as an antigen, provide protection and rigidity
x Cell membrane: serve as a barrier through which materials
enter and exit the cell.
#2 Capsule:
acts as an antigen, has feeding importance, sticking
features and cause disease
#3 Mesosome:
role in metabolism
#4 Fimbriae:
helps in motility, jerky movement, has sticking
feature and acts as an antigen
#5 Pilus:
helps in reproduction(conjugation)
x Ribosomes: protein formation
#6 Nucleoid:
transcription and translation
#7 Chromosomes:
hereditary material
#8 Droplets:
helpful in storage
#9 Flagella:
act as an antigen and helps in motility
#10 Plasmid:
has special features of resistance and infection
Appendages external to bacteria
Fimbriae
-Made up of fimbrine protein and range hundreds in number.
- Helps in motility and jerky movement
-Acts as a poor antigen thus helps in recognition
-Used for attachments and formation of biofilms
e.g. fimbriae of
bacteria Neisseria gonorrhoeae helps to colonize in mucous
membrane and fimbriae of E.coli helps to adhere in small
intestine
-Acts as a disease causing agents after attachment
- Cause ascending infection e.g. in excretory system
Pilli
-They are longer then fimbriae and range in number from 1 to
10.
-They are made up of pillin protein. Its function is reproduction
i.e. sexual reproduction in bacteria known as conjugation. (F+
,the bacteria which give genetic material and F-
, which receive).
The rest of the functions are same as fimbriae.
Glycocalyx (capsule)
Prokaryotic cell sometimes secrete a substance outside the cell wall
known as glycocalax.
- If the substance is organized and is firmly attached to the cell
wall, the glycocalyx is described as a capsule.
- If the substance is unorganized and only loosely attached to
the cell wall, the glycocalyx is described as a slime layer.
- If a number of bacteria are present close together and the
capsule of a single cell cannot identified the layer formed is
known as saline layer.
- If glycocalyx is removed from cell wall or if it is not present at
all then a thin layer is present known as “S” layer.
- If a colony forms LPS capsule the appearance of colony will be
smooth.
- If a colony forgets to form LPS capsule the colony will b rough.
- If protein capsule is present in colony then appearance will be
rough
- If protein capsule absent then the appearance will be smooth.
Function
- Protection because of slimy nature
- Protection against immune system so they can cause disease
- Capsule can serve as a food source
e.g. Streptococcus mutants.
- Used for attachment
x Serve as a good antigen.
Flagella
Flagella are long filamentous appendages that propel bacteria
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This topic is important for the ICDS Supervisor Exam.Click HERE.
You can Go to more posts Regarding ICDS Supervisor Kerala PSC Here.
More ICDS Supervisor Kerala PSCSociology Notes Here
ICDS Supervisor Kerala PSC Homescience Notes Here
ICDS Supervisor Kerala PSC Food ,Nutrition and Health Notes Here
Very useful lessons
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