Download Bacteria - Dickinson ISD

Bacteria:
Classification and
Structure
What are the 6 Kingdoms?
 Archaebacteria
 Eubacteria
 Protists
 Fungi
 Plants
 Animals
We are looking at the first two
 Archaebacteria
: Extremists.
Larger of the two
kingdoms. Contain a variety of
organisms
 Eubacteria:
Archaebacteria
 Live
in extreme locations:
 Oxygen-free
environments
 Concentrated
 Hot,
salt-water
acidic water
EUBACTERIA
Bacteria – all are prokaryotic meaning they
do not have a nucleus.
Bacteria are unicellullar cells (one cell only)

They are found almost everywhere:
-water
-air
-soil
-food
-skin
-inside the body
-on most objects
Clean skin has about 20 million
bacteria per square inch
The tip of a
needle
The red and
yellow dots
are bacteria
Structure of Bacteria
Two
parts to Bacteria
Structure:
Arrangement
Shape
3 Shapes of Bacteria
Bacteria are classified by shape into 3 groups:
Spiral:
spirilla
rod-shaped:
bacilli,
bacillus
Round:
cocci
7 Major parts of a Bacteria Cell
•Capsule
•Cell wall
•Ribosomes
•Nucleoid
•Flagella
•Pilli
•Cytoplasm
CAPSULE
Capsule
 keeps the cell
from drying out
and helps it
stick to food or
other cells
CELL WALL
Cell wall
Thick outer
covering that
maintains the
overall shape of
the bacterial
cell
Cell Wall – determined by Gram Staining.
Gram positive – stain purple because they
have peptidoglycan in their cell wall.
Thicker cell wall, but less pathogenic.
Gram negative – stain red because they lack
peptidoglycan in their cell wall. Thinner cell
wall, but generally more pathogenic .
Penicillin
kills bacteria
by making holes in their
cell walls.
Unfortunately, many
bacteria have developed
resistance to this
antibiotic.
RIBOSOMES
Ribosomes
 cell part where
proteins are made
 Ribosomes give
the cytoplasm of
bacteria a granular
appearance in
electron
micrographs
NUCLEOID
Nucleoid
 a ring made
up of DNA
PILLI
Pilli
 hollow hair-like
structures made
of protein
allows bacteria
to attach to
other cells.
Pilli-singular
Pillus-plural
FLAGELLA
Flagella
 a whip-like
tail that some
bacteria have
for locomotion
Classification

Movement
 Non-motile
 Flagella
 Gliding
– whiplike structure
– secrete a slime
CYTOPLASM
Cytoplasm
 clear jelly-like
material that
makes up most
of the cell
Metabolic Diversity

Chemoheterotrophs: - take in organic molecules for
energy.

Photoheterotrophs: - use sunlight and photosynthesis
for energy but must also take in organic molecules for
energy.

Photoautotrphs:- Use sunlight energy and
photosynthesis to make their own food.

chemoautotrophs: - use carbondioxide to make
energy but do not require light.
Energy Release

Oblique aerobes: require oxygen for life.

oblique anaerobes: must live in the absence
of oxygen.
Example: Clostridium botulinum

Facultative anaerobes: Can live with or
without oxygen.
Example: Escherichia coli
Example:
Mycobacterium tuberculosis
Reproduction of Bacteria
•Binary Fission- the process of one organism
dividing into two organisms
•Fission is a type of asexual reproduction
•Asexual reproduction- reproduction of a
living thing from only one parent
How?...
The one main (circular)
chromosome makes a
copy of itself
Then it divides into two
Reproduction of Bacteria
BINARY FISSION
Bacteria dividing
Completed
Reproduction of Bacteria
•The time of reproduction depends on how
desirable the conditions are
•Bacteria can rapidly reproduce themselves in
warm, dark, and moist conditions
•Some can reproduce every 20 minutes
(one bacteria could be an ancestor to
one million bacteria in six hours)
Bacterial Cell &
Nucleiod DNA Ring
DNA replication
Cell wall synthesis
Cell separation
Spore formation
Endospore•a thick celled structure that forms inside
the cell
•they are the major cause of food poisoning
•allows the bacteria to survive for many years
•they can withstand
boiling, freezing, and
extremely dry conditions
•it encloses all the
nuclear materials
and some cytoplasm
Bacteria Survival
Bacillus subtilis
Endospore-the black section in the middle
highly resistant structures
can withstand radiation, UV light, and
boiling at 120oC for 15 minutes.
Bacteria Survival – Nutrition
parasites – bacteria that feed on living things
saprophytes – use dead materials for food
(exclusively)
decomposers – get food from breaking down
dead matter into simple chemicals
important- because they send minerals
and other materials back into the soil so
other organisms can use them
Harmful Bacteria
• some bacteria cause diseases
•Animals can pass diseases to humans
Communicable Disease –
Disease passed from one organism to another
This can happen in several ways:
•Air
•Touching clothing, food, silverware, or toothbrush
•Drinking water that contains bacteria
Harmful Bacteria
Human tooth with accumulation of bacterial
plaque (smooth areas) and calcified tartar
(rough areas)
Helpful Bacteria (Importance of bacteria)
•Decomposers help recycle nutrients into the
soil for other organisms to grow
•Bacteria grow in the stomach of a cow to
break down grass and hay (cellulose)
•Most are used to make antibiotics
•Some bacteria help make insulin
•Used to make industrial chemicals
Helpful Bacteria
E.coli on small intestines
Helpful Bacteria
•Used to treat sewage
Organic waste is consumed by the bacteria,
used as nutrients by the bacteria, and is no
longer present to produce odors, sludge,
pollution, or unsightly mess.
•Foods like yogurt, cottage & Swiss cheese,
sour cream, buttermilk are made from bacteria
that grows in milk
Controlling Bacteria
3 ways to control bacteria:
1) Canning- the process of sealing food in
airtight cans or jars after killing bacteria
•endospores are killed during this process
2) Pasteurization- process of heating milk
to kill harmful bacteria
3) Dehydration- removing water from food
•Bacteria can’t grow when H2O is removed
•example: uncooked noodles & cold cereal
Controlling Bacteria
Antiseptic vs. Disinfectants
Antiseptic- chemicals that kill
bacteria on living things
•means – “against infection”
Examples: iodine, hydrogen peroxide,
alcohol, soap, mouthwash
Disinfectants- stronger chemicals that
destroy bacteria on objects or nonliving
things
Summary on the structure of bacteria
Structure
Function
Cell Wall
Protects and gives shape
Outer
Membrane
Protects against antibodies (Gram Neg. Only)
Cell
Membrane
Regulates movement of materials, contains
enzymes important to cellular respiration
Cytoplasm
Contains DNA, ribosomes, essential compounds
Chromosome Carries genetic information
Plasmid
Contains some genes obtained through recomb.
Capsule &
Slime Layer
Protects the cell and assist in attaching cell to
other surfaces
Endospore
Protects cell agains harsh enviornments
Pilus
Assists the cell in attaching to other surfaces
Flagellum
Moves the cell
37
Bacteria and Diseases.
 Some
bacteria cause diseases
--Disease causing bacteria
are called PATHOGENS.
Disease
Bacteria
and
Disease
Pathogen
Areas
Mode of
Botulism
affected
transmission
Clostridium botulinum
Nerves
Improperly preserved
food
Cholera
Vibrio cholerae
Intestine
Contaminated water
Dental Caries
Streptococcus mutans, sanguis,
salivarius
Teeth
Environment to mouth
Gonorrhea
Neisseria gonorrhoeae
Urethra,
fallopian
Sexual contact
Lyme disease
Berrelia burgdorferi
Skin, joints
Tick bite
Rocky
Mountain SF
Rickettsia recketsii
Blood, skin
Tick bite
Salmonella
Salmonella
Intestine
Contaminated food,
water
Strep throat
Streptococcus pyogenes
URT, blood,
skin
Sneezes, coughs, etc.
Tetanus
Costridium tetani
Nerves
Contaminated wounds
Tuberculosis
Mycobacterium tuberculosis
Lung,
bones
coughs
Leprosy is a
bacterial
infection
that
decreases
blood flow to
the
extremities
resulting in
the
deterioration
of toes, ears,
the nose and
the fingers.
DENTAL CARIES
CHOLERA
ROCKY MOUNTAIN SF
LYME DISEASE
SALMONELLA
STREP THROAT
TETANUS
TUBERCULOSIS
Plants, Fungi & Animal Cells

Plants Only




Cell wall of cellulose
Central vacuole
Chloroplasts

Animals Only


Lysosomes
Centrioles
Fungi Only
– Cell wall of chitin
– Central vacuole
– No chloroplasts