Question

Why do lipids spontaneously form the following arrangement when placed in water? a. Each lipid has a hydrophobic end and a hydrophilic head that act like magnets; the hydrophobic ends attract to hydrophilic heads, creating a bilayer. b. The individual lipid subunits form covalent bonds to create the polymeric quaternary structure, which is a bilayer. c. The covalent bonds formed between the polar amino acids of the fatty acid chains are stronger than the electrostatic interactions with water, forcing water molecules out. d. The hydrophobic nature of the lipid chains drives them together, away from the water, while the polar-head groups form favorable electrostatic interactions with water.

Answer 1

Lipids spontaneously form the following arrangement when placed in water because the hydrophobic nature of the lipid chains drives them together, away from the water, while the polar-head groups form favorable electrostatic interactions with water. Option D is the answer.

Step-by-step explanation:

Option d correctly describes the spontaneous arrangement of lipids in water. Lipids, being amphipathic molecules, have hydrophobic tails and hydrophilic heads. In an aqueous environment, such as water, the hydrophobic tails aggregate together, minimizing their contact with water, while the hydrophilic heads interact with water molecules. This arrangement, known as a lipid bilayer, is the fundamental structure of biological membranes.

Options a, b, and c are incorrect. Option a inaccurately describes a magnetic-like interaction, option b incorrectly references covalent bonds for lipid interactions, and option c misrepresents the forces involved, as the interactions are primarily hydrophobic and hydrophilic in nature.

Option D is the answer.