AP BIOLOGY

Detailed explanation-1: -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-2: -The “tail” of the molecule is made up of two fatty acids, which are hydrophobic and do not dissolve in water. Following the rule of “like dissolves like", the hydrophilic head of the phospholipid molecule dissolves readily in water.

Detailed explanation-3: -This makes phospholipid molecules have a hairpin shape. The head of the hairpin is very polar and therefore likes to associate with water (it is hydrophilic), while the two fatty acid chains (the “tails") are very non-polar and tend to avoid water (hydrophobic) and associate with other hydrocarbon chains.

Detailed explanation-4: -The fatty acids are lipids that contain long-chain hydrocarbons terminated with a carboxylic acid functional group. Because the long hydrocarbon chain, fatty acids are hydrophobic (“water fearing”) or nonpolar.

Detailed explanation-5: -Phospholipids are a group of lipids which are composed of two fatty acids tails combined with a phosphate group. One of those fatty acid tails has a double bond, causing a kink in it. These fatty acids are hydrophobic, they are repelled by water. In contrast, the other part of a phospholipid is hydrophilic.