4 (4 points). How would you describe the difference in cell structures between a thermophile and a psychrophile? Include mention of cell membrane construction and enzyme/protein structure at least. Solution Thermophilic bacteria have more long chain fatty acids or lipids which maintain the membrane fluidity. They have more tetraether lipids that increase the membrane stability. Hence they survive in high temperatures. Thermophiles also have a high level of K+ salts which protect the DNA and proteins by forming hydrophilic shell. Thermophiles have have acidic aminoacids. psychrophiles grow at very low temperatures. They have high polyunsaturated and methyl- branched fatty acids, and/or a shorter acyl-chain length which are generally present in cis configuration . This increases membrane fluidity and reduces the interactions between the membrane preventing freezing at low temperature. They have cryoprotectants and antifreeze agents..