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Explore the crucial role of bacteria in human life, from digestion to disease, and the significance of their communication abilities. Learn about the diverse shapes, movements, and relationships of prokaryotic organisms, shedding light on their essential functions and impact. Delve into the classification, reproduction, and genetic exchange among bacteria and archaea, uncovering their evolutionary connections and survival strategies in various environments. Discover the key roles of bacteria as decomposers, nitrogen fixers, and more, highlighting their vital contributions to ecosystems and human activities.
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http://www.ted.com/talks/bonnie_bassler_on_how_bacteria_communicate.htmlhttp://www.ted.com/talks/bonnie_bassler_on_how_bacteria_communicate.html
Bellwork: Tues. April 11, 2017 Write the “red” down immediately…. We will watch part of a short TED video to get the answers... • You have about 100X more bacterial genes playing a role in or on your body than your human genes – so … 1. You “are” only ___% to ___% human (genes) -> or ____% to ____% bacterial (genes.) (Creepy) 2. Why is the discovery that bacteria can talk to each other so important?
E. Coli O157:H7 can make you very sick. Streptococcus can cause strep throat. This E. coli helps you digest food. bacteria • Single celled prokaryoticorganisms • Very small 1 to 5 micrometers • Need a microscope to see • Can be found on most materials and surfaces • Billions on and in your body right now
Classifying Prokaryotes Prokaryotes are classified as Bacteria or Archaea: 2 of the 3 domains of life.
most abundant microorganismson Earth • DNA is in cytoplasm (not in a membrane-bound nucleus like eukaryotes.) • ex: E. coli.
Kingdom Bacteria live almost everywhere: fresh water, salt water, on land, on and within the bodies of humans and other eukaryotes. Escherichia coli
Bacteria • cell wall that protects the cell from injury and determines its shape. • containpeptidoglycan sugars and amino acids that surrounds the cell membrane. • Some bacteria, have a second membrane outside the peptidoglycan wall that makes the cell especially resistant to damage.
peptidoglycan This layer becomes important in gram staining
Kingdom Archaea • Cell walls of archaea lack peptidoglycan, and their membranes contain different lipids. • DNA sequences of key archaea genes are more like those of eukaryotes (us) than those of bacteria. • Scientists think archaea and eukaryotes are related more closely to each otherthan to bacteria.
Archaea • live in extremely harsh environments. • One group produces methane gas and live in environments with little or no oxygen, such as thick mud and the digestive tracts of animals. • Other archaea live in extremely salty environments - Utah’s Great Salt Lake, or in hot springs where temperatures approach the boiling point of water.
Size, Shape, and Movement • bacteria are distinguished by shape, arrangement, whether they move and how they move. • Some prokaryotes do not move. Others are propelled by flagella. Some glide slowly along a layer of slimelike material they secrete.
What do they look like? • Three basic shapes • Rod shaped: bacilli (buh-sill-eye) • Round shaped: cocci (cox-eye) • Spiral shaped • Some exist as single cells, others cluster together Bacilli Cocci Cluster of cocci Spiral
Arrangements of Bacteria • Coccus Two (pair) = diplococcus Chain = Streptococcus Cluster = Staphylococcus • Bacillus • Two (pair)= diplobacillus • Chain = Streptobacillus • Coccobacillus • Vibrio = curved • Spirillum • Spirochete • Square • Star Chapter 4
Bacteria: 3 types of symbiotic relationships: Parasitic (+ , - ) Mutualistic: (+ , + ) both symbionts benefit. Example: Nitrogen fixationin cyanobacteria: Commensualistic (+ , 0 )
Reproduction • binary fission: when a prokaryote has grown so that it has nearly doubled in size, it replicates its DNA and divides in half producing 2 identical cells – asexual form of reproduction
endospore: thick internal wall enclosing DNA and cytoplasm when growth conditions become unfavorable – • many prokaryotic cells form these • can remain dormant for months or even years.
Conjugation When prokaryotes exchange genetic information - bridge forms between 2 bacteria, & a plasmid(bacterial genetic material) moves from 1 to the other. (New genetic combination – evolve = better survival
Conjugation • Many plasmids carry genes that enable bacteria to survive in new environments or to resist antibiotics that might otherwise prove fatal. • evolve= better survival genetic diversity in populations of prokaryotes.
Bellwork: Wed. March 12, 2017 Name the bacteria type and draw it!: 1. 2. 3. https://www.youtube.com/watch?v=-iE-JbtxB6w
The Importance of Bacteria (Prokayotes) • Decomposers: break down complex organic molecules into simpler molecules in soil and in rotting plant material such as fallen logs… • industrial sewage treatment, helping to produce purified water and chemicals http://www.qrg.northwestern.edu/projects/marssim/simhtml/info/whats-a-decomposer.html
Nitrogen Fixers: Rhizobium bacteria live symbiotically in nodules of legume roots on soybeans, beans, clover converting atmospheric nitrogen into a form that is useable by plants.
Nitrogen gas (N2) makes up 80 % of Earth’s atmosphere, but only prokaryotes can convert N2 into useful forms.
Nitrogen fixation:converts nitrogen gas into ammonia (NH3). Ammonia: (NH3)can then be converted to nitrates that plants use, or attached to amino acids that all organisms use. https://www.youtube.com/watch?v=4NKGS4bj7cc
Photosynthetic prokaryotes (cyanobacteria A.K.A. blue green algae) are among the most important producers (of oxygen)on the planet. https://www.youtube.com/watch?v=uU00tg98Jjw
Food chains are dependent upon prokaryotes as producers of food and biomass.
Human uses of Bacteria Yogurt is produced by the bacterium Lactobacillus. https://www.youtube.com/watch?v=9HL5iOE3kT8 https://www.youtube.com/watch?v=TjPvSpKh5oI Cheese: https://www.youtube.com/watch?v=aKXsYmYpCIk
Some bacteria can digest petroleum and remove human-made waste products and poisons from water. WRITE THIS ON THE BACK: • Bioremediation —boosting microbial activity by ensuring a steady supply of such nutrients— https://www.youtube.com/watch?v=gM5bQscTjgs
Human uses of Bacteria Other bacteria are used to synthesize drugs and chemicals through the techniques of genetic engineering. • https://www.youtube.com/watch?v=zlqD4UWCuws
Human uses of Bacteria Bacteria and archaea adapted to extreme environments may be a rich source of heat-stable enzymes that can be used in medicine, food productioN AND BEYOND EARTH? https://www.youtube.com/watch?v=mJgi1Kz6Ejc