Prokaryotes:
Download
Report
Transcript Prokaryotes:
Prokaryotes:
Archaea & Bacteria
The Tree of Life
All
living things
classified in three
domains:
Bacteria
Archaea
Eukarya
Amazing Living Things
Microbes
important to all life:
Decomposition
Over half of Earth’s
More
biomass
bacterial cells than human cells in
your body!
Prokaryotes
Prokaryotes have:
DNA
or RNA, ribosomes, cytoplasm, plasma
membrane
Most prokaryotes have a cell wall, a capsule
(around the cell wall) and a flagellum
Prokaryotes don’t have:
Organelles
such as nucleus, chloroplasts,
mitochondria.
Generalized Prokaryote
Nucleoid DNA
Plasmid DNA
Cytosol
Flagellum
Capsule
Plasma
Membrane
Cell Wall
Bacteria/Archaea
Habitats (name a place, and they live
there!)
They
are specialists
human
skin, mouth, respiratory tract, large
intestine, urogenital tract, etc.
salty
Dead Sea
extreme
archea
Aerobes
pH
in deep sea vents: 90-106o C
and anaerobes
Some Prokaryotes Thrive in Extreme Conditions
Cyanobacteria in Yellowstone
Hot Springs
Archaea
Unique
lipid membranes, cell walls, and
RNA
EXTREME Environments:
Swamps,
hot springs, vent communities, cow
stomachs
concentrated salt environments
hot, acidic environments
Bacteria
Shape:
Cocci
- round
Bacilli - rod
Spirilla - spirals
Three Common Bacterial Shapes
(b)
(a)
(c)
bacillus
cocci
spirillus
The Prokaryote Flagellum
Flagella
Bacterium
Bacteria
Reproduction
Reproduction
is asexual, by simple
splitting (binary fission)
Daughter
cells are genetic clones of
the parent cell
Binary Fission
DNA
Benefits of Bacteria
Symbiosis (mutualism)
Ruminants’
digestive tracts
Nitrogen fixing in soil, nodules on certain legumes
Bacteria on/in the human body: intestines and vitamin K
and B12
Biodegradation - oil
Food production - cheese, yogurt, sauerkraut
Decomposers
Our Relationship With Bacteria
Harmful Bacteria
Some cause disease = pathogenic
In humans:
Strep throat
Toxins - tetanus, botulism
Pneumonia
"Flesh-eating" bacteria
Plague
Tuberculosis
Cholera
Lyme disease
ANTIBIOTICS= anti bacterial!!!
The Causes of Tooth Decay
Transmission of Bacterial
Pathogens
Airborne
Water
Food
Direct (skin contact, blood, and other body
fluids)
Insects and other hosts such as deer tick
(Lyme).
Germ Theory of Disease
Theory that microorganisms are the cause
of disease.
1859 – Louis Pasteur
Credited
with the idea that human diseases
were caused by bacteria and viruses (germ
theory)
Very important discovery in the field of
medicine
Also created vaccinations to prevent disease
Infectious Diseases
Average age of death, in first world
countries, jumped 30+ years in last century
due
to antibiotics
enhanced hygiene and nutrition
Antibiotic-resistant infections on the rise in
hospitals in the U.S.
This
is due to bacterial evolution in response
to widespread use of antibiotics!