OBJECTIVE LIFE SCIENCE
CELL BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the phosphate group in the ‘head’ region
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the glycerol in the ‘head’ region
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double bonds in the fatty acid ‘tail’
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a saturated fatty acid tail
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Detailed explanation-1: -In the fatty acid tail, there are two double bonds. So, cholesterol does offer fluidity, but the here correct answer is (d) because the double bonds and fatty acid tails contribute the most to membrane fluidity because it’s a hydrocarbon tail, which means it has carbons with hydrogen linked to it.
Detailed explanation-2: -The fatty acid chains are the uncharged, nonpolar tails, which are hydrophobic. Since the tails are hydrophobic, they face the inside, away from the water and meet in the inner region of the membrane. Since the heads are hydrophilic, they face outward and are attracted to the intracellular and extracellular fluid.
Detailed explanation-3: -The degree to which fatty acid chains are saturated also affects membrane fluidity. The cis double bonds found in unsaturated fatty acids create kinks in the fatty acid chain that prevent lipids in the membrane from packing together tightly, thus decreasing the surface area over which lipids interact.