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Two groups of Archaea
- 1.) Euyarcheota (broader metabolism)- Methanogens
- 2.) Crenarchaeota - thermophiles that metabolize sulfer (anaerobic reduction or aerobic respiration)
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What makes archaea biochemistry unique?
- Mathane production
- no peptidoglycan - pseudomurein
- differences in glycolytic pathway
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How are Archael lipids different?
- L-glycerol instead of D
- Ether links, not ester
- Branched chains of lipids - isoprene and all saturated
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Archaeal Genome vs Bacterial vs Eukarya
- Bacteria: Circular, have operons
- Eukarya: Introns, TATA, TFB, prot similiar to histones
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Crenarchaeota Characteristics
- Irregular shapes
- Unique lipid - Crenarchaeol
- Most live at high temps and anaerobic/acidic env.
- utilize minerals that were reduced by high temp water
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Desulfurococcales Characteristics + ex
- No cell wall - S-layer (mono prot or glycoprot)
- Reduce sulfer at high temps
- Variable shapes
- ex : Ignicoccus pyrodictium
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Sulfolobales Characteristics + ex
- Oxidize sulfer at high temp
- produce sulfuric acid
- Needs heat and acidity, grows easily with conditions
- No cell wall - thick S-layer
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Crenarchaeota - Which kind are found where? What temps? Examples
- High numbers in ocean, amount depends on season
- Mesophilic - ocean, plant roots ex: Nitrosopumliales
- Psychrophilic - ice and seawater in antarctica ex: cenarachaeum (deepwater sponge)
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Nitrosopumilales
- Oxidize ammonia, and fix CO2
- common in ocean and soil
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Euryarchaeota: Methanogenesis
- Needs anaerobic env
- Hydrogen=electron donor
- CO2, acetate, formate=electron acceptor - creates methane
- Cofactors - hold c during process - coenzyme M, methanofuran, cofactor F420
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Where are methanogens found?
Anaerobic env - landfill, marine sediment/flood soil, Rumen, Human gut
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Euryarchaeota: Halophile characteristics
- Require >1.5 M NaCl (grow best at 4.3 M=pH 7)
- Organic molecules raise internal osmolarity
- High GC DNA (prevents denaturation of DNA in high salt)
- elongated, round, flattened shape
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What is Bacteriorhodopsin?
found in Euryarchaeota, and pumps out H+
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What is Halorhodopsin?
Pumps in Cl-
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Where does power for flagellum come from?
Na gradients created by a proton gradient that is used to pump out NA
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