Which of the following correctly describes the behavior of fatty acids placed in aqueous solution?
A) They will spontaneously form micelles, with the hydrophobic heads clumping together and the hydrophobic tails pointing outwards.
B) They will dissolve in the solution with adequate stirring.
C) It is impossible to get fatty acids to interact with water as they will form an oily layer on top of the water.
D) They will spontaneously form micelles, with the hydrophobic tails clumping in the center of the micelle and the hydrophilic heads pointing outwards.
Explanation
Fatty acids are amphipathic molecules, with a charged hydrophilic head and a long hydrocarbon tail that is hydrophobic. To minimize the contact area between the water and the hydrophobic tails, the fatty acids will spontaneously form micelles, small spherical structures with the fatty acid tails clumped in the middle. Thus, (D) is the right answer.
Want more MCAT practice?
We’ve got options for every schedule and learning style!
From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative full-length practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!
Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT Advisor using the form below. No obligation, just expert advice.