The right answer is D
These are essential constituents:
• membranes of the body's cells (neurons, enterocytes): to preserve their viscoelasticity thus optimized cellular exchanges
• the nervous system (brain and nerves)
• the neurotransmitter acetylcholine
• bile fluid (micelle formation) synthesized by the liver and stored in the gallbladder
These polar lipids having a hydrophilic part which affords them an affinity with the aqueous medium, and a lipophilic part which allows them an affinity with fatty acids which do not have affinities with aqueous media allow the solubilization of apolar triglycerides in lipophobic aqueous media (the intestine is an aqueous medium)
The glycerol and phosphate portion of the molecule is said to be hydrophilic (which likes water) while the fatty acids are hydrophobic (which does not like water). The hydrophilic part is soluble in water while the hydrophobic part is not (it is soluble in lipids).
The glycerol-phosphate portion is hydrophilic whereas the fatty acids are hydrophobic. The phospholipids are often represented by a ball, the hydrophilic portion, and two "legs", the hydrophobic fatty acids.
Placed in water, the phospholipid molecules tend to form a monomolecular layer (a molecule of thickness) where only the hydrophilic portions are in contact with water.
