BIO22900
Spring 2025
Janakiraman and Pukatzki
Test your understanding - 2.
MULTIPLE CHOICE:
1. Detergents are best able to dissolve oil from fabric or dishes during washing because:
A) detergents are nonpolar, they increase the size of the oil droplet, allowing the water to
be more effective at removing the oil.
B) the nonpolar end is associated with water molecules, while the charged end interacts
with the oil droplet.
C) the positively charged end is associated with water molecules, while the negatively
charged end interacts with the oil droplet.
D) the negatively charged end is associated with water molecules, while the positively
charged end interacts with the oil droplet.
E) the charged end is associated with water molecules, while the nonpolar end interacts
with the oil droplet
2. A bacterium is suddenly expelled from a warm human intestine into the cold world outside.
Which of the following adjustments might the bacterium make to maintain the same level of
membrane fluidity?
A) produce lipids with hydrocarbon tails that are longer and have fewer double bonds
B) produce lipids with hydrocarbon tails that are shorter and have more double bonds
C) decrease the amount of cholesterol in the membrane
D) decrease the amount of glycolipids in the membrane
3. Which type of lipids are the most abundant in the plasma membrane?
A) phospholipids
B) glycolipids
C) sterols
D) triacylglycerides
4. Membrane lipids are capable of many different types of movement. Which of these does NOT
occur spontaneously in biological membranes?
A) moving between lipid layers
B) lateral movement
C) rotation around the long axis of a fatty acid
D) flexing of hydrocarbon chains
5. Cholesterol serves several essential functions in mammalian cells. Which of the following is
NOT influenced by cholesterol?
A) membrane permeability
B) membrane fluidity
C) membrane rigidity
D) membrane thickness
6. Which of the following statements about the carbohydrate coating of the cell surface is FALSE?
A) It is not usually found on the cytosolic side of the membrane.
Spring 2025
Janakiraman and Pukatzki
Test your understanding - 2.
MULTIPLE CHOICE:
1. Detergents are best able to dissolve oil from fabric or dishes during washing because:
A) detergents are nonpolar, they increase the size of the oil droplet, allowing the water to
be more effective at removing the oil.
B) the nonpolar end is associated with water molecules, while the charged end interacts
with the oil droplet.
C) the positively charged end is associated with water molecules, while the negatively
charged end interacts with the oil droplet.
D) the negatively charged end is associated with water molecules, while the positively
charged end interacts with the oil droplet.
E) the charged end is associated with water molecules, while the nonpolar end interacts
with the oil droplet
2. A bacterium is suddenly expelled from a warm human intestine into the cold world outside.
Which of the following adjustments might the bacterium make to maintain the same level of
membrane fluidity?
A) produce lipids with hydrocarbon tails that are longer and have fewer double bonds
B) produce lipids with hydrocarbon tails that are shorter and have more double bonds
C) decrease the amount of cholesterol in the membrane
D) decrease the amount of glycolipids in the membrane
3. Which type of lipids are the most abundant in the plasma membrane?
A) phospholipids
B) glycolipids
C) sterols
D) triacylglycerides
4. Membrane lipids are capable of many different types of movement. Which of these does NOT
occur spontaneously in biological membranes?
A) moving between lipid layers
B) lateral movement
C) rotation around the long axis of a fatty acid
D) flexing of hydrocarbon chains
5. Cholesterol serves several essential functions in mammalian cells. Which of the following is
NOT influenced by cholesterol?
A) membrane permeability
B) membrane fluidity
C) membrane rigidity
D) membrane thickness
6. Which of the following statements about the carbohydrate coating of the cell surface is FALSE?
A) It is not usually found on the cytosolic side of the membrane.
