Download Archaea, Bacteria Kingdom-TEA - KCI-SBI3U

Have you heard?
• Genus Demodex; live exclusively on human
• 2 species: D.folliculorum (top) and D.brevis (bottom)
http://blogs.discovermagazine.com/notrocketscience/2012/08/31/everythingyou-never-wanted-to-know-about-the-mites-that-eat-crawl-and-have-sex-onyour-face/
Two types of cells:
Prokaryote
vs. Eukaryote
Prokaryote vs. Eukaryote
Characteristics
Size
Prokaryotes:
Archaebacteria and
Eubacteria
1-10 m
Eukaryotes:
Protists, Plants, Fungi,
Animals
100-1000 m
Genetic materials - Circular DNA
- DNA in nucleus
including plasmids, not bounded by membrane
bound by a membrane - No plasmid
- Genome made up of - Genome made up of
a single chromosome several chromosomes,
thus contains many
more genes than
prokaryotes
Cell division
Binary fission
Mitosis and meiosis
Reproduction
Asexual is common
Sexual is common
Prokaryote vs. Eukaryote (cont.)
Characteristics
Prokaryotes:
Archaebacteria and
Eubacteria
Eukaryotes:
Protists, Plants, Fungi,
Animals
Number of cells
Unicellular
Most are multicellular
Organelles
No membrane-bound
organelles such as
mitochondria, chloroplast
etc.
No nucleus
Membrane-bound
organelles present
Metabolisms
-Many carry out
metabolism under no O2
condition
-Metabolism processes
carried out in the
cytoplasm
-Most require O2
-Metabolism processes
carried out in membranebound organelles such as
mitochondria, chloroplast
etc.
Endosymbiosis Theory
How have prokaryotes possibly become eukaryotes?
Eukaryotic cells are believed to be the result of a symbiotic
union of separate prokaryotic cells
Kingdom Archaebacteria and
Eubacteria
(generally referred as
Bacteria)
•
•
•
•
•
Shared characteristics of
Archaebacteria and
Eubacteria
no nucleus
All single-celled.
no membrane-bound organelles
DNA as a single chromosome.
Reproduce asexually by binary
fission.
Kingdom: Archaebacteria
• Archae means primitive or early
• Often live extreme environments
Eg. high salt concentrations,
temperature or acidity;
• Most live in environments with no
oxygen
• Hypothesis: all life kingdoms are
descended from the ancestors of this
group
Classification of Kingdom
ArchaeaBacteria
• By their habitats
A. Anaerobic methanogen: those live in O2free places (e.g. gut of animals and
produce CH4)
B. Halophiles: salt-loving archaea
C. Thermophiles: those inhabit hot, acidic
environment such as hot springs
Kingdom Eubacteria or Bacteria
Kingdom Bacteria
Classification
1. Shapes
2. Respiration
3. Reaction to staining
4. Reproduction
1. Bacterial shapes
http://www.youtube.co
m/watch?v=6p9e0ool
bmE
Classification – Shape
Singular Plural
coccus
cocci
bacillus
bacilli
Shape
round
rod
spirrillum spirrilla
spiral
Advantages
Resists drying out
greater surface area
= higher nutrient
absorption
can move through
fluids with less
resistance
Kingdom Bacteria
2. RESPIRATION
Classifying bacteria by respiration
1) Obligate aerobes: require oxygen
2) Obligate anaerobes: grow only in
absence of oxygen
3) Facultative anaerobes: can survive
with or without oxygen
Nutrition: vocabulary revision
• Autotrophs: make their own food
• Heterotrophs: obtain food by
breaking down organic molecules
from their environment
• Chemo- derived from chemical
reactions
• Photo- derived from sunlight
Bacterial Nutrition
Mode of nutrition
Photoautotroph
Energy
source
Light
Carbon
source
CO2
Inorganic
chemicals
CO2
Light
Organic
compounds
Organic
compounds
(e.g. cyanobacteria)
Chemoautotroph
(e.g. Ferrobacillus
ferrooixdans)
Photoheterotroph
(e.g. Heliobacter polyri)
Chemoheterotroph
(e.g. Methanococcus
jannaschii )
Organic
compounds
4. Bacterial reactions to being stained
• Gram staining: a staining technique by
Hans Christian Gram in 1884
• Divide bacteria into 2 groups:
Gram negative
Peptidoglycan
absent in cell wall
Gram positive
Peptidoglycan
present in cell wall
Gram staining procedure
BACTERIAL ASEXUAL REPRODUCTION
Called “binary fission”
• bacterial DNA replicates and divides
• a cross wall develops and the two
genetically identical cells separate
http://www.youtu
be.com/watch?v
=DY9DNWcqxI4
&feature=related
True!
Conjugation- not true
sexual reproduction
• Cell to cell contact is made
with a cytoplasmic bridge
• Plasmids (small circular
DNA); contain genes
different from those in the
bacterial chromosome
• Plasmids are transferred
from the donor to the
recipient
• Recipient now has new
genes from donor (ie.
Gene for antibiotic
resistance)
ENDOSPORE FORMATION
• Adaptation to survive unfavourable
conditions eg. Anthrax forms spores
• Cell wall becomes thick
• resistant to heat
and not easily
destroyed
• bacterium emerges
when suitable
conditions return
USEFUL BACTERIA
• Production of
vinegar
• fixing nitrogen in
soils
• dairy products
(cheese, yogurt….)
• decomposers in
nutrient cycles
• source of some
Antibiotics
• Clean up oil spill
HARMFUL EFFECTS
BACTERIAL DISEASES
1. Leprosy
2. Tetanus
3. Botulism
4. Cholera
DEFENSE AGAINST DISEASE
• Body provides own defenses (skin, acidic
stomach, lysozyme in eyes, immune
system)
• sterilization/disinfection of surfaces can
reduce disease further (wash your hands)
• Antibiotics are chemicals that kill bacteria
but don’t harm host cells
• Bacteria have evolved to resist many of
today’s antibiotics
Antibiotics and Antiseptics
• Joseph Lister created the first antiseptic, an acid
to spray on tables and instruments before
surgery (1860)
• The Discovery of Penicillin (1928)
•
•
•
•
Alexander Fleming
Noticed mold growing on petri dishes
Bacteria did not grow where the mold was
He isolated the chemical that killed bacteria, but
it was not stable
• Howard Flory continued the work, later stabilized
the chemical
• Fleming and Flory received the Nobel Prize in
1945
Bacterial growth:
- Zones of inhibition around
the disks shows
the effectiveness of the
antibiotics
Antibiotic resistance:
Ability of bacteria to
grow in the presence
of chemicals meant to
destroy them
What is the zone of
inhibition on this agar?
Which disk(s) is
most effect at
inhibiting the
growth of bacteria
on this agar?
Drug screening: Bacteria can be grown on agar
plates to check for antibiotic resistance
Which Petri disk show
more antibiotic resistance?
Bonnie Bassler - PrincetonU
How Bacteria Talk to each
other?
•http://www.ted.com/talks/lang/eng/bonnie_bassler_
on_how_bacteria_communicate.html
Quorum sensing:
the phenomenon
whereby the
accumulation of
signalling
molecules enables
bacteria to sense
their number so
they can launch
group behaviour
(e.g. virulence etc.)
Review
1. Label the bacteria by shape
dicocci
streptococci staphylococci
2. What is a bacteria called that must live in
oxygen?
• Obligate aerobe
3. How do bacteria reproduce?
• Binary fission (asexual) & conjugation
4. Bacteria on a
pin. What
shape?
a.Cocci
b.Bacilli
c.Spirilla
5. What survival
advantage
does this
shape bring to
the bacteria
For your interest
• Next 2 slides connect with your
antibiotic resistance reading
articles
Drug- resistant Superbugs
non-typhoidal
salmonella
Vancomycin-resistant
Staphylococcus aureus
Neisseria gonorrhoeae
Streptococcus
pneumoniae
tuberculosis
Pseudomonas
aeruginosa
Get Smart: Know When Antibiotics Work
Q. What kinds of infections are caused by viruses and
should not be treated with antibiotics?
• cold, flu, sore throat (except strep. throat), cough,
bronchitis, ear infections are viral infections
shouldn’t be cured with antibiotics
Q. Can one strain of bacterium
become resistance to multiple drugs?
• Absolutely YES!
E.g. P. aeruginosa causes eye
infections, skin rashes, ear
infections, after surgery infection,
widely spread in hospital
Multi drug-resistant
Pseudomonas
aeruginosa
http://www.cdc.gov/getsmart/antibiotic-use/antibiotic-resistance-faqs.html
Kingdom Bacteria
Kingdom Bacteria