LIBERTY UNIVERSITY MSCI 660
INTRACELLULAR MEMBRANE TRAFFIC
AND CELLULAR SORTING QUIZ 2026
PRACTICE SOLUTION QUESTIONS WITH
ACCURATE ANSWERS GRADED A+
⩥ What is meant by selectively permeable?
Answer: The membrane allows some substances to pass while restricting
others
⩥ What is the structure of the cell membrane?
Answer: A phospholipid bilayer with embedded proteins
⩥ What is the thickness of a cell membrane?
Answer: Approximately 6-8 nm
⩥ What is the composition of a typical plasma membrane?
Answer: ~40-45% lipid; ~45-50% protein; ~5-10% carbohydrate
⩥ What is the structure of a phospholipid?
Answer: Hydrophilic phosphate head and two hydrophobic fatty acid
tails
, ⩥ What does amphiphilic mean?
Answer: A molecule with both hydrophilic and hydrophobic regions
⩥ How do phospholipids arrange in water?
Answer: Heads face water; tails face inward away from water forming a
bilayer
⩥ What structures can phospholipids form?
Answer: Micelles, liposomes and bilayers
⩥ What is a phospholipid bilayer?
Answer: A double layer with hydrophobic tails inward and hydrophilic
heads outward
⩥ What is the difference between saturated and unsaturated fatty acids?
Answer: Saturated fatty acids have carbon to carbon single bonds;
unsaturated have one or more carbon to carbon double bonds
⩥ How do unsaturated fatty acids affect membrane fluidity?
Answer: They increase fluidity due to kinks(carbon to carbon bonds)
preventing tight packing
INTRACELLULAR MEMBRANE TRAFFIC
AND CELLULAR SORTING QUIZ 2026
PRACTICE SOLUTION QUESTIONS WITH
ACCURATE ANSWERS GRADED A+
⩥ What is meant by selectively permeable?
Answer: The membrane allows some substances to pass while restricting
others
⩥ What is the structure of the cell membrane?
Answer: A phospholipid bilayer with embedded proteins
⩥ What is the thickness of a cell membrane?
Answer: Approximately 6-8 nm
⩥ What is the composition of a typical plasma membrane?
Answer: ~40-45% lipid; ~45-50% protein; ~5-10% carbohydrate
⩥ What is the structure of a phospholipid?
Answer: Hydrophilic phosphate head and two hydrophobic fatty acid
tails
, ⩥ What does amphiphilic mean?
Answer: A molecule with both hydrophilic and hydrophobic regions
⩥ How do phospholipids arrange in water?
Answer: Heads face water; tails face inward away from water forming a
bilayer
⩥ What structures can phospholipids form?
Answer: Micelles, liposomes and bilayers
⩥ What is a phospholipid bilayer?
Answer: A double layer with hydrophobic tails inward and hydrophilic
heads outward
⩥ What is the difference between saturated and unsaturated fatty acids?
Answer: Saturated fatty acids have carbon to carbon single bonds;
unsaturated have one or more carbon to carbon double bonds
⩥ How do unsaturated fatty acids affect membrane fluidity?
Answer: They increase fluidity due to kinks(carbon to carbon bonds)
preventing tight packing
