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Unformatted text preview: upper legs to retain more fluidity in reduced temperatures. Brain cell membranes in ground squirrels become more solid during hibernation. Phospholipids containing more polyunsaturated fatty acids are more fluid than those with fewer polyunsaturated fatty acids. Cholesterol in membranes reduces fluidity as well. There are times when membranes need more or less fluidity, and molecular composition provides for sure membrane flexibility. Phospholipid Movement Unsaturated/Saturated With Cholesterol Many materials that enter or leave the cell are water-soluble; the fatty acid layers serve as a barrier to their free entry. Proteins in the membrane are required to move these substances through the membrane. Lipids generally pass through the membrane more easily....
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This note was uploaded on 12/29/2011 for the course BIO 151 taught by Professor Edwards during the Spring '10 term at SUNY Stony Brook.
- Spring '10