Prokaryotes
Chapter 19
Prokaryotes!
Y. pestis (cause of bubonic
plague)
• The small wonder… First inhabited
the earth ____________!
• Continued to rule alone for 1.5 billion
years until they gave rise for more
complex organisms
• Still exist today (bacteria) and are still
one of the most fierce predators, as
well as important helpers associated
with human health.
• Have ____________
• Even though they are in ________
_____________________they are
very similar in morphology
ESCHERICHIA COLI is a type of bacteria that
lives in the intestinal tract, aiding the digestive
• Generally single celled
process by suppressing the growth of harmful
bacteria and synthesizing vitamins
Prokaryotes are broken into two major
groups… diverged a long time ago
Archaea
• Has its ______________
____________(some
match Eukaryotes)
• Use ________________
____________similar to
eukaryotes
• _____________________
• Some Carbon chains,
mostly branched
Bacteria
• Has unique rRNA
sequences
• Replicates with _______
____________________
• ______________________
_______________cell wall
(Gram Stain)
• Unbranched carbon chains
in the membrane lipids
Prokaryotes are divided by the way they
get nourishment
• Earliest life needed to be
autotrophs (make their own
food). Need Energy (make ATP…
to do so they need a carbon
source!)
– Photoautotrophs: Energy from
______________… carbon from
_______ (Cyanobacteria… No
Archaea just bacteria)
– Chemoautotrophs_____________
_______________ and break their
bonds for energy… get their
carbon from ______ (many
Archaea metabolize this way)
More Prokaryote divisions
• Once some Autotrophs existed
organisms can start eating other
organisms (_________________)
– Photoheterotrophs: Energy from
___________, Carbon from ________
_________________ (some purple
and green bacteria)
– Chemoheterotrophs: Get energy by
_________________________, also
get their carbon from _____________
______________ (similar to animals…
largest group, includes E. coli and
SOME Archaea)
Purple
bacteria
Anthrax (Bacillus
anthracis )
Archaea are found in unusually harsh
environments
• Very similar to Eukaryotes in many
of their DNA sequences
• Can obtain nutrients in the same
ways and be the same size as
bacteria
• Resemble ancient life because they
live in environment close to the
original earth’s environment
– Extreme halophiles: Live in
______________________ like
the dead sea
– Extreme thermophiles: Live in
_____________________
– Methanogens: Live without
oxygen and _________________
Bacteria come in 3 basic shapes
• Spherical shaped (Cocci), often in
clumps (streptococcus: strep throat)
• Rod-Shaped (often called _________)
and live singularly… not touching
• Curved or Spiral shaped (vibros,
spirilla or ______________). Syphilis
is caused by a spirochete
Some bacteria cause disease...
• Any disease causing agent is called a
_______________________
• Half of human diseases are caused by
pathogenic bacteria
• Classified into two mechanisms
– ___________ Producing:
• Bacteria ________________ that is
pathogenic
– usually VERY dangerous… just a little
infection can kill you)
– Ex: Clostridium botulinum
– _________________Producing:
• Bacteria themselves _____________
_____________________________
– generally more mild but do include
major illness like food poisoning and
typhoid fever
Vibrio cholerae causes a
life-threatening diarrhea
using both endo and exo
toxins
Virulence and Prevention
• Virulence of a pathogen is
measured by LD50… the amount of
pathogen that will kill 50% of those
exposed to it
• The __________________________
__________________________and
dangerous the microbe.
• With bacteria most treatments are
_______________ and the best way
to prevent onset is with good
The Komodo dragon carries at
_______________________
least 3 strains of highly virulent
bacteria in its mouth…this way
it __________________________
____________________________
Current uses for Bacteria
• Biological warfare: Not a new
idea…
– during the Middle Ages plague
victims were used as ‘bombs’ and
tossed into enemy lines
– Europeans unknowingly and
knowingly gave bacterial (and viral)
infections to the people they were
trying to concur (Yellow fever and
the American Indians ring a bell?)
– US started using researching
anthrax, as well as botulism back in
1943
• Now this bioterrorism is becoming a
threat to the US… Anthrax easily
spreads and aerosolizes
Not all bacteria are bad! (Bioremediation)
• Cleaning the environment: Bacteria
can also be used for good
– Used to ______________________
_____________________(clean out septic
tanks and help keep pipes flowing)
– ____________________(there are natural
bacteria that metabolize oil waste and
they can be cultivated to clean up habitats
that have been damaged by humans)
It’s diversity that helps prokaryotes continue to
survive
• Unique structural features that
allow prokaryotes to make up for
their small singular size…
– Prokaryotic ____________
(allows for locomotion)
– _________(allows for adhesion
to a favorable environment)
– _____________ : Resting
structure for bacteria in an
unfavorable environment… lets
it hang out until conditions get
better (used like seed in plants)
• Clostridium and Bacillus
anthraces form endospores
Eukaryotes
Chapter 20
Review
• Prokaryotes: Domains Archaea and Bacteria
•
•
•
•
Protista: The Junk Kingdom
Fungi
Plantae
Anamalia
Right Now
Before the Final
In the beginning (or a couple million years
later)
•
1.
2.
Eukaryotes evolved from prokaryotes using a couple cool
features
Membrane infolding…When the ________________________
___________________________________________ (like ER)
______________________… One cell living within another,
benefiting both (like Mitochondria and chloroplasts)
Do you have a junk drawer?
• The protista are a junk kingdom… which is really probably a lot
of kingdoms
• They are placed together because they don’t fit in the other
kingdoms, not because they have something in common.
• They can be classified by how they look– but DNA doesn’t
always agree
Fungus- like Protists
Ancient
Protists
Plant- like Protists
Animal- like Protists
For now we’ll go with this
• Protista is broken into 3 major groups based
on their lifecycle… most groupings are nonmonophylogenetic.
– Diploid dominant (like animals)
– Alternation of generations (like plants)
– Haploid/ gametophyte dominant (like fungi)
**Note– these are not evolutionary linages
Dominant Diploid Generation
• Diploid dominant… heterotrophic
and sometimes parasitic
– Flagellates: __________________,
include Giardia which lives in the Giardia
intestine, and Trypansoma which
lives in the blood and causes African
sleeping sickness
– Shelled Amoebas: Secrete a shell
then extend their ______________
(fake feet)out to move, they also use
them for endocytosis
- Alveolates... Next page
Dominant Diploid Generation…
continued
Alveolates
• Apicomplexa: specialized with
complex organelles for being a
___________________. Include
Plasmodium which causes
malaria
• Ciliates: Move via cilia. Have 2
kinds of nuclei (1 macro and
several micro) ______________
______________________. Live
in aquatic environments
• Some _____________: Although
they ARE alveolates we will
discuss them with Algae because
most are photosynthetic
Alternation of Generations
• When a species
alternates LIVE
GENERATIONS.
• It lives _____________
___________________
• Plants have distinct
alternations… so do
these next protista
Unicellular Algae
• Act like single celled
plants… (photosynthetic,
autotrophic)… not a
monophyletic group
• Dinoflagellates: distinct
look per species. Two
flagella that cause them to
spin around.
______________________
___________________and
can be deadly. (some
_________)
• Diatoms: Huge marine food
source. Have a shell made
of __________ (look
glassy). Float near the
surface of the ocean
• Green Algae: single celled,
multiple life stages… more
to come
More on Green Algae
• ______________________________
______________________________
______________________________
______________________________
• Their early evolution can be ‘seen’ in
modern species
– Chlamydomonas seems to be the
precursor to Volvox.
– When Volvox reproduces the cells
that leave (red or green biflagellate
cells) look like those of
Chlamydomonas.
– When Volvox is in its growth state it
appears as an aggregation of those
same Chlamydomonas - like cells
Multicellular Algae
• Most complex algae…
– __________________________________
__________________________________
__________________________________
• Brown algae (not all brown) ______________
_________________________, diverged from
diatoms. Form large kelp forests that are
indispensable to fish, otters and even gray
whales (have “hold fasts” instead of roots)
• Red Algae: can __________________. Life in
tropical waters and play an important role in
reef building (have unicellular members–
dinoflagellates)
• Multicellular green algae: _____________
___________________(like many plants do).
This is a cycle of haploid and diploid organisms
being formed
Cellular Slime Molds
• Gametophyte dominant
• Unicellular and multicellular life
stages
• ____________________________
____________________________
… making them fungus-like
• CASE EXAMPLE: Dictostelium
– Feeds on bacteria… if they are
plentiful it leads a happy solitary,
single celled (amoeboid) life.
Reproducing by mitosis and moving
very little.
– When bacteria is scarce the _______
______________________________
(using cAMP signals) to form a colony
with more motility.
– Moves to what it thinks might be a
better place __________________
______________________________
(the colony differentiates its cells…
crazy)