DIVERSITY Bacteria and Archaea bacteria prokaryotes archaea eukaryotes
DIVERSITY!!! Bacteria and Archaea
bacteria prokaryotes archaea eukaryotes
Bacteria & Archaea All Prokaryotes First appeared on earth 3. 4 bya (~1. 7 by before eukarya) Incredibly numerous and diverse
Bacteria & Archaea: Trivia ~You have more bacterial cells in your body than your own cells: ______% of cells in your body are bacterial ~One ml of sea water contains about 1 million bacteria ~Estimated that the total # of bacteria (and archaea) alive today to be 5 x 1030. If lined up end to end would make a chain longer than Milky Way Galaxy (587, 460, 167, 340, 730 miles). *only 9 -10, 000 of them identified!* ~Make up half of the biomass on earth
Why should you care about prokaryotes? • Bacteria keep you going – Mouth: Compete with pathogenic bacteria and yeast for food (ECOLOGY at work ) – Large intestine • 100 billion • Produce vitamins
Why should you care? • Bioremediation: microorganisms return environment altered by contaminates back to original condition ‘seeding’
Why should you care? • Biofuels: fuels produced from living organisms that contain over 80% renewable materials • Scientists on quest to discover new bacteria that can use alternative electron acceptor or donor and convert it to a useable energy source (http: //www. sciencedaily. com/releases/2008/01/080106202952. htm )
Bacteria introduction activity • One person, but you can work in teams. 15 minutes
Why should you care? • Nutrient Cycling: Without bacteria, you would have no nitrogen
Based on what you know about carbon, Where do you get your nitro A. The air you breathe (about 78% of atmosphere is N 2) B. The plants you eat (which get it from the air) C. The plants you eat (which get it from the soil) D. The animals you eat (which get it from the air) E. The animals you eat (which get it from the plants)
Nitrogen from the air? A. The air you breathe (about 78% of atmosphere is N 2) B. The plants you eat (which get it from the air) D. The animals you eat (which get it from the air) Nitrogen makes up 78% of our atmosphere (as N 2), however, atmospheric nitrogen is: very stable and can’t be broken down to a usable form N 2 is triple-bonded N N very stable difficult to cleave So, plants and animals cannot use N 2 directly from the air
How does all of this unusable nitrogen get converted into something plants and animals can use? BACTERIA!
Lithotrophs • Organisms that use inorganic compounds as their energy source • Many microbes including Bacteria and Archaea
Nitrogen from soil via plants and animals? C. Nitrogen from eating plants which get it from soil and from E. eating animals that eat those plants YES We want to know: 1. How does the Nitrogen get to the soil? 2. Does all of that atmospheric nitrogen just go to waste b/c it can’t be directly taken in by plants and animals?
Nitrogen in soil comes from: • Animals excreting ammonia => usable nitrogen • Dead Plants and animals decompose=> biomolecules broken down to smaller molecules =>usable nitrogen
How do bacteria supply us with nitrogen? I. Nitrogen fixation II. Nitrification III. Denitrification Rhizobium: N-fixing bacteria that lives symbiotically in the roots of certain plants like beans and peas
Nitrogen Fixation Atmospheric (inorganic) N 2 taken in by plants then converted to NH 4 by bacteria in plant root nodules or soil bacteria also get organic N from dead matter, break it down to amino acids and nucleotides and then to NH 4 Nitrogen Cycle (e. g. Rhizobium) NH 4 still not usable by plants Nitrification NH 4 converted to NO 3 (only form plants This NO 3 now taken up by plants (and used it to build amino can use) acids) & converted back to atmospheric N 2 via denitrification
This is just one example of bacteria’s role in nutrient cycling Different species of bacteria cycles other inorganic molecules of carbon, phosphorous and sulfur similar to the nitrogen cycle This is not just a good example of how necessary Bacteria are but also a good example of their diversity (endless variety of metabolic pathways) Nitrogen fixation activity: one person, but you may work in groups- due today
Why should you care? Taq polymerase – PCR reactions => amplify DNA from very small amount – Heat to denature DNA, copy, anneal Repeat – Copying DNA requires polymerase, a protein – High temperature environment denatures proteins. – NOT proteins adapted for high temperatures though!!!!
Speaking of “extremophiles”… • Astounding diversity of prokaryotes – Habitat – Nutrient acquisition – Metabolism
Trivia: Habitat As a group, archaea and bacteria can live just about anywhere Salt Lakes (Salt conc. 10 x higher than ocean) Hot Springs (100ºC) Soda lakes (p. H 9 -10) Glaciers, Arctic ocean (~1ºC) Acidic mud in yellowstone (p. H 1)
Trivia: Nutrient acquisition Bacteria/Archea activity question 2. Prokaryotes Energy source Light Carbon Source CO 2 Mode of nutriti on photoauto troph
Trivia: Metabolism (cellular respiration and alternatives) Fermentation & Aerobic and Anaerobic cellular respiration Recall Aerobic Cell Respiration: e- donor e- acceptor C 6 H 12 O 6 + O 2 ADP + Pi + energy ATP CO 2 + 6 H 20 + energy By-products For most organisms, cell respiration means: Sugar is consumed: electron donor Oxygen is taken in: electron acceptor
Trivia: Metabolism Bacteria & Archaea can use a wide variety of molecules as e- donors and e- acceptors in cell respiration (anaerobic respiration) The use of various molecules as electron donors and acceptors results in bacteria 1. “cleaning up each other’s mess” 2. Co-existing in one type of environment without competing for the same energy resources.
ACTIVITY: METABOLIC DIVERSITY TO ECOLOGICAL DIVERSITY
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