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Descrição
FlashCards por J yadonknow, atualizado more than 1 year ago
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Criado por J yadonknow
quase 7 anos atrás
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| Questão | Responda |
| What is a psychrophile? | MO that has an optimal growth at 15c or lower Max=20c |
| Which extremophiles survives at -12c? | Psychromona |
| Lowest enzyme temperatures | Some enzymes at -20c |
| What climates does a psychrotolerant MO? | Can grow at 0c Optima= 20c-40c Found in temperate climates |
| What are snow algae? | Chlamydomonas nivalis surface of permanent snowfall Red-pigmented spore in bad conditions |
| Protein adaptations to cold | their 1' structure has more polar amino acids, fewer weaker bonds 2' has more a-helix than b-sheets, gives protein greater flexibility Cold shock proteins |
| Membrane adaptations to cold | High unsaturated and short fatty acid chain content |
| What do cells produce to prevent ice crystals? | Cryoprotectants, solutions that prevent formation of ice crystals in cells. |
| What optimum temperature do thermophiles grow at? | 45'c |
| Hyperthermophile charas | found in hot springs prokaryotic only Short generation times |
| Which extremophile is the most thermotolerant? | Methanopyrus, 122'c. |
| Species gradient | As boiling water leaves hot springs it cools, creating a thermal gradient Different species grow at different temperatures along the gradient |
| Thing learned from studying species gradients | Pros can grow at much higher 'c than Eu's Archaea are most thermophilic of all pro |
| Do photoT or non-photoT org tolerate heat better? | Non-photo Found from studying species gradients |
| Heat stable protein adaptations | More ionic bonds between basic/acidic aa |
| DNA protections for hyperthermophiles (2) | Highly hydrophobic to Increased DNA stability Reverse DNA gyrase induces positive supercoils |
| Membrane adaptations in thermophiles | More saturated fatty acid, form a strong hydrophobic environment Longer chain FA= increased surface area=increased mpt |
| membrane adaptions in HYPERthermophiles | Don't have FA Have c40 isoprenes that are ether bonded to glycerol phosphate Forms a lipid monolayer |
| Describe the characteristics of acidophiles | Grow at pH 5.5 or below Max = 7 |
| Why is an optima of 1 rare? | scarcity of pH 1 in nature |
| What cellular component is crucial for acidophiles? | Stability of cytoplasmic membrane is critical A high [H*] is required for membrane stability |
| Describe the characteristics of alkaliphiles | pH 8+ or above Max = pH 11 Cytoplasmic pH near neutrality Use Na+ gradients instead of H+ |
| Bacteria in saltlakes | Solute potential is very negative constant hypertonic conditions |
| "physiological drought" | Extremely hard to extract water from surroundings |
| What's the name for salt loving and salt tolerant bacteria? | Halophiles Halotolerant |
| How do halophiles adapt to salty conditions? | Increase internal solute potential using compatible solutes |
| What sort of solutes? | Solutes that are highly soluble but don't interfere with cellular metabolism, such as proline residues. |
| What is characteristic of a compatible solute? | Compatible solutes aren't charged and won't strip the solvent shell of proteins |
| Name some examples of compatible solutes (5) | Sucrose, Trehalose, Glycine, Betaine, Glycerol |
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