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