BACTERIA

BACTERIA

Bacteria are very small

Bacteria

are very

small

compared

to cells

with nuclei

This is a pore in

human skin and

the yellow spheres

are bacteria

BACTERIA LIVE ALMOST

EVERYWHERE

Hot

springs

Volcanic

vents on the

sea floor

Chemosynthetic bacteria use the

sulfur in the “smoke” for energy.

BACTERIA CAN LIVE WITH

OR WITHOUT OXYGEN

BACTERIAWHERE: Everywhere--> *Food

*water

*soil

*your BODY!

AGE: ...probably the oldest life form on Earth

*fossil bacteria found in rocks

3.5 billion years old!

DESCRIPTION: single-celled organism

*prokaryotic

WITHOUT A NUCLEUS

MORE BACTERIA!

CLASSIFIED by SHAPE

*COCCUS(round)

Coccus

bacteria

are

sphere

or

ball

shaped

CLASSIFIED by SHAPE -continued

SPIRILLUM(spiral)

Spirillium bacteria have a corkscrew shape

CLASSIFIED by SHAPE -continued some more!

Bacillus(rod)

Bacillus

bacteria

are rod

or

sausage

shaped

usually form COLONIES, or GROUPS.These three shapes...

DIPLO (pairs)

Colonies, continued...

STREPTO(chains)

Colonies, continued...

STAPHYLO(clusters)

Colonies, continued...

TETRA(groups of four)

BACTERIA Names...…given by the COLONY PREFIX and the SHAPE SUFFIX

Examples

STREPTOCOCCUS

chains of round bacteria

STREPTO= chains COCCUS= round+

BACTERIA THAT CAUSE

DISEASE

• Some bacteria cause

diseases. Disease causing

bacteria are called

pathogenic.

Diplo-bacteria

occur in pairs,

such as the

diplococcus

bacteria that

causes a STD.

Staphylo -

bacteria occur

in clumps, such

as this

staphylococcus

bacteria that

causes common

infections of

cuts

A staph infection!

Strepto-

bacteria occur

in chains of

bacteria, such

as this

streptococcus

bacteria that

causes some

types of sore

throats

STREP THROAT

WHITE BLOOD CELL ABOUT TO EAT

A BACTERIA!

What is the shape of the bacteria?

DENTAL CAVITIES

Helicobacter

pylori

is the

pathogenic

bacteria

that can

causes ulcers

Leprosy is a

bacterial

infection

that

decreases

blood flow to

the

extremities

resulting in

the

deterioration

of toes, ears,

the nose and

the fingers.

TUBERCULOSIS

GRAM STAINING BACTERIA

• The Gram stain classifies

bacteria into gram-positive

and gram-negative

The Gram Stain

Gram-Positive

THE CELLS WILL BE

“PURPLE “

Gram-Negative

THE CELLS WILL BE

“RED”

• Gram-positive bacteria tend to be

killed by penicillin and detergents.

• Gram-negative bacteria are more

resistant to antibiotics.

Gram Stain

Examples of Gram Stains

Gram Positive Rods

and Cocci

Gram Negative Rods

and Cocci

Figure 3.11b

What color are the Gram positive bacteria?

BACTERIA Survival...--> Most bacteria obtain food from other living things.

(like us)

--> some eat dead things -DECOMPOSERS

--> some are PARASITES -. live off other living things

*these may cause DISEASE

*or may actually HELP the host!

--> Example of “helping” Bacteria:

Bacteria in your intestine helps with

digestion and produces vitamin K.

Helpful BACTERIA-->FOOD PREPARATION

cheese

butter

I mean“Yogurt”!

fermentation

Harmful BACTERIAFOOD SPOILAGE

Botulism caused by

Clostridium botulinum

E. coli

found in beef-->

Salmonella

Controlling the growth of BACTERIAHow to limit BACTERIA REPRODUCTION

** TEMPERATURE (Pasteurization)

(Pasteurization)

Louis Pasteur

**CHEMICALS

heat kills bacteria

*boil *steam

*Bleach *iodine

Controlling the growth of BACTERIA (more!)

** Removing MOISTURE

*No water,

no bacteria!

SALTING**RADIATION

*use of radiation to “zap” bacteria!

BACTERIAL STRUCTURE

43

STRUCTURE OF BACTERIAStructure Function

Cell Wall Protects and gives shape

Gelatinlike

capsule

Protects against antibodies Helps the bacteria stick to things.

Cell Membrane

Regulates movement of materials

Cytoplasm Contains DNA, ribosomes, essential compounds

Chromo-some

Carries genetic information

Ribosome Makes proteins

Flagellum Moves the cell

CLASSIFICATION OF

BACTERIA

• Bacteria are classified into two kingdoms.

• Eubacteria

• Archaebacteria

Blue-green bacteria are CYANOBACTERIA. They are producers.

KINGDOM: EUBACTERIA