BIOH111 PLASMA MEMBRANE STRUCTURE AND FUNCTION EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++

BIOH111 PLASMA MEMBRANE STRUCTURE AND FUNCTION EXAM QUESTIONS AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++ What is a lipid bilayer? Biological membrane composed of phospholipids. What are the main components of a lipid bilayer? Phospholipids, cholesterol, and glycolipids. What is the function of a lipid bilayer? To separate areas of a cell with different conditions. What is the composition of phospholipids? 75% of the molecule, with hydrophilic heads and hydrophobic tails. What is the role of cholesterol in the lipid bilayer? It stabilizes the membrane and reduces fluidity. What are the three main parts of cholesterol? OH group, stiff steroid ring, and hydrocarbon tail. Where does cholesterol reside in the lipid bilayer? With the fatty acid tails of phospholipids. What is the function of glycolipids? To stabilize the membrane and enable cellular recognition. What is the composition of glycolipids? 5% of the molecule, with hydrophilic heads and hydrophobic tails. Where are glycolipids situated in the membrane? On the outside of the membrane. What are the two types of membrane proteins? Integral and peripheral. What is the function of integral proteins? Ion channel, transporter, and receptor. What is the structure of integral proteins? They extend across the whole membrane and have hydrophobic and hydrophilic parts. What is the function of peripheral proteins? Cell identifier, linker, and enzyme. Where are peripheral proteins located in the membrane? Attached to the polar head of membrane lipids and integral proteins. What are the functions of the plasma membrane? Protection, regulation of substance movement, and communication. What is the structure of the plasma membrane?