By Alexis Avila & Nilanka Lord. Relatively new discovery so we don’t know too much about them ...
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Transcript of By Alexis Avila & Nilanka Lord. Relatively new discovery so we don’t know too much about them ...
Archaebacteria are not fully understood!
Relatively new discovery so we don’t know too much about them
Classification is very difficult Originally classified under Kingdom
Monera with the rest of the bacteria Studies showed that 50% of their
genes did not resemble those of other bacteria
Characteristics of Archaebacteria
Can only live in areas without oxygen
Extremophillic (thrive under extreme conditions)
Prokaryotic (very similar to bacteria) Single-celled No nucleus No membrane bound organelles Navigate using one or more flagella
Size and Shape of Archaebacteria
Volume is about one-thousandth that of eukaryotes
Can be cocci, bacilli, or spirilla in shape
Parts of Archaebacteria
Cell wall that lacks peptidoglycan Phospholipid bilayer
Composed of glycerol-ether lipids, unlike bacteria
One or more flagella
Reproduction
Reproduce asexually via binary fission (prokaryotic) Binary fission: when a single DNA
molecule replicates and two identical cells are created from original cell
Ecological Significance
World's most prolific methane producers Play a big role in digestion in many
organisms Some are found in the gut of humans and
assist in digestion Forms symbiotic relationships with:
▪ Giant tube worms (Riftia pachyptila)▪ Termites▪ Herbivores (like cows and horses)
Suspected to play a role in periodontal disease, but not proven
Modes of Nutrition
Archaebacteria have 4 ways of getting food: Photoautotrophic- Calvin Cycle (light energy +
CO2) Chemoautotrophic- reverse Krebs cycle
(inorganic chemicals + CO2) Photoheterotrophic- use light + organic
chemicals to make food Chemoheterotrophic- undergo respiration,
either Krebs, TCA, or Citric Acid cycle, and then ETC (organic chemicals + CO2)
Uniqueness
Thermotaxis (movement toward extreme temperatures)
Evolution of thermotaxis due to lack of competition for survival
Groups of Archaebacteria
Methanogens
(Make METHANE)
Thermoacidophiles
(Love HEAT & ACID)Halophiles(Love SALT)
Characteristics of Methanogens
Found in oxygen-free environments Produce methane gas from HO2 & CO2
Can live and produce in conditions other bacteria can’t survive in
Most are coccoid or rod-like in shape (few exhibit a plate-like shape)
Cluster of coccoid methanogenshttp://faculty.college-prep.org/~bernie/sciproject/project/Kingdoms/Bacteria3/methano
gens.htm
Methanobrevibacter ruminantium
Found in the guts of rumen (like cows)
Turn H2 into CH4 (methane)
Cows release this methane into the atmosphere
Scientists looking for a way to limit their production of methane
http://202.114.65.51/fzjx/wsw/newindex/tuku/MYPER/a2/750.htm
Characteristics of Halophiles
Require salt-rich environments to survive (due to high internal salt concentration)
Like plants, they use sunlight as a source of photosynthetic energy
Get their color and chemical energy from bacteriorhodopsin (a light-sensitive pigment)
Most are rod-shaped (bacilli)
Halobacterium halobium
Prevalent bacteria in the Great Salt Lake
Can survive in salt concentrations 10x saltier than that of the oceans
http://domescobar.blogspot.com/2011/11/oito-criaturas-da-terra-que-poderiam.html
Owens Lake Bed (Sierra Nevada, California)
http://school.nettrekker.com/goExternal?np=/external.ftl&pp=/error.ftl&evlCode=255279&productName=school&HOMEPAGE=H
Characteristics of Thermoacidophiles
Can live and thrive in extremely hot, sulferic, and/or acidic environments
Include:Thermophiles= thrive in extremely high temperatures
Acidophiles= pH tolerant (function at 1-5 pH)
Sulfolobus= thrive in sulfur-rich environments
Desulfonauticus submarinus
Live in giant, deep-sea tube worms called Riftia pachyptila
Share a symbiotic relationship with the tube worms
Make food and energy for the tube worms via chemosynthesis
http://bioweb.uwlax.edu/bio203/s2007/rossing_jaco/images/tubeworms.jpgGOVwww.nsf.gov.jpg
Sulfolobus solfataricus
Found in sulfur-rich, acidic environments
Grows optimally at 80⁰C
Capable of living in extremely acidic circumstances (1-5 pH)
http://www.sulfosys.com/tl_files/sulfosys/sulfolobus/Zelle.jpg
1) All of the following are examples of substances found in bacteria or archaea EXCEPT:
a) peptidoglycanb) flagellinc) bacteriorhodopsind) chitine) phycobilins
2) Which of the following contains prokaryote organisms capable of surviving extreme conditions of heat and salt concentration?a) archaeab) virusesc) protistsd) fungie) plants
Sources
Archaebacteria http://ic.galegroup.com/ic/scic/ReferenceDetailsPage/ReferenceDetailsWindow?di
splayGroupName=Reference&disableHighlighting=false&prodId=SCIC&action=e&windowstate=normal&catId=&documentId=GALE%7CCV2644030155&mode=view
http://plantphys.info/organismal/lechtml/archaea.shtml http://www.nature.com/ismej/journal/v1/n1/full/ismej20078a.html http://school.nettrekker.com/goExternal?np=/external.ftl&pp=/error.ftl&evlCode=
240911&productName=school&HOMEPAGE=H
http://www.pnas.org/content/101/16/6176.long Methanogens
http://faculty.college-prep.org/~bernie/sciproject/project/Kingdoms/Bacteria3/methanogens.htm
http://www.angelfire.com/ks3/lditton/archaebacteria.html http://www.enotes.com/science/q-and-a/methanogens-halophiles-thermoacidophi
les-3-groups-156123
http://www.hindawi.com/journals/arch/2010/945785/ Halophiles
http://waynesword.palomar.edu/plsept98.htm http://mmbr.asm.org/content/62/2/504.full
Thermoacidophiles http://go.galegroup.com/ps/retrieve.do?sgHitCountType=None&sort=DA-SORT&in
PS=true&prodId=GPS&userGroupName=lcpsh&tabID=T003&searchId=R1&resultListType=RESULT_LIST&contentSegment=&searchType=BasicSearchForm¤tPosition=2&contentSet=GALE%7CA168664452&&docId=GALE|A168664452&docType=GALE&role=ITOF