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THE BACTERIA
QURATULAIN MUGHALBATCH IVDOCTOR OF PHYSICAL THERAPYISRA UNIVERSITY
PROCARYOTES
Are organisms with simple structures. The absence of a membrane-bound nucleus. They lack intracellular membranous structures such
as mitochondria and chloroplast. The structures of sexual reproduction are absent. Contain a highly complex substance peptidoglycan in
their cell walls. Reproduce themselves by binary fission. They are singled-celled organisms.
TOXONOMIC SCHEME
Suggested by ROBERT H. WHITTER. All procaryotic cells are placed in KINGDOM
PROCARYOTAE, or MONERA.
PROCARYOTES
BACTERIA ARCHAEA
BACTERIA
[Gk. Bacterion, rod] It’s the largest group of procaryotic cells. All bacteria [singular, bacterium] are unicellular
(but variations are found among them).
Can be identified on the basis of various characteristics:
Cellular morphology
Staining reactions
Cultural characters
Biochemical characters
Source of energy
MORPHOLOGICAL CHARACTERS
SIZE
Most bacteria are between 1-10ɱm in length.
SHAPE
Rod-shaped: bacillus [plural, bacilli] Spherical: coccus [ plural, cocci] “S”-shaped: spirilla [singular, spirillum]
ARRANGEMENT OF BACILLIARRANGEMENT OF BACILLI
DIPLOBACILLI
Divide across their short axis and remain in the form of a pair.
STREPTOBACILLI
In the form of chain.
PALISADE
Some bacilli line up side-by-side
CHINESE LETTER-LIKE ARRANGEMENT
Bacilli are aligned at acute angles.
ARRANGEMENT OF COCCIARRANGEMENT OF COCCI
DIPLOCOCCI
Single plane and remain in pairs.
STREPTOCOCCI
Single plane and remain attached in short or long chains.
STAPHYLOCOCCI
Multiple planes and appears in the form of bunch of grapes.
TETRACOCCI
Divided into two regular planes and form a group of four cells.
SARCINAE
Divide in three planes and remain attached in cubical packets of eight cells.
TYPES OF SPIRAL BACTERIA
VIBRIOS
Appear as curved rods.
SPIRILLA
Are helical bacteria resembling with a corkscrew.
SPIROCHETES
Are highly flexible and helical bacteria.
GENUS HALOARCULA
Rectangular and flat in shaped
GENUS STELLA
Star-shaped bacteria.
MONOMORPHISM
Bacteria which remain unchanged through generations.
POLYMORPHISM
Some bacteria have genetic ability to have many shapes at a time. And called POLYMORPHIC.
THE FUNCTIONAL ANATOMY
•COMPONENTS OF BACTERIAL CELL EXTERNAL TO THE CELL WALL•BACTERIAL CELL WALL•COMPONENTS INTERNAL TO THE CELL WALL
COMPONENTS THAT ARE PRESENT EXTERNAL TO CELL WALL
Glycocalyx Flagella Pili
GLYCOCALYX
A glycoprotein-polysaccharide covering that surrounds the cell membranes of some bacteria
FLAGELLA
A lash-like appendage that protrudes from the cell body.
Bacteria contain flagella called flagellated bacterium and without flagella called nonflagellated or aflagellated.
TYPES OF FLAGELLAR ARRANGEMENT
LOPHOTRICHOUS
A bacterial cell with two or more flagella at one or both poles.
AMPHITRICHOUS
Having a single flagellum at each end
PERITRICHOUS
Having a uniform distribution of flagella over the body surface.
MONOTRICHOUS
Having a single flagellum at one pole
BACTERIAL CELL WALL
Composed of peptidoglycan (polysaccharides + protein)
maintains the overall shape of a bacterial cell Mycoplasma are bacteria that have no cell
wall and therefore have no definite shape.
COMPONENTS INTERNAL TO THE CELL WALL
Cytoplasmic Membrane Transmembrane proteins Peripheral proteins Ribosomes Granules