Cell Membrane Quiz

What is the primary function of the plasma membrane?

• To provide energy to the cell

• To control traffic into and out of the cell

• To produce proteins

• To store genetic information

What characteristic of the plasma membrane allows some substances to cross it more easily than others?

• Rigidity

• Selective permeability

• Thickness

• Color

What are the main components of cellular membranes?

• Carbohydrates and nucleic acids

• Lipids and proteins

• Vitamins and minerals

• Sugars and starches

What is an amphipathic molecule?

• A molecule with only hydrophilic regions

• A molecule with only hydrophobic regions

• A molecule with both hydrophilic and hydrophobic regions

• A molecule with no distinct regions

How are phospholipids and proteins arranged in the fluid mosaic model of the membrane?

• In a rigid, static structure

• In a fluid structure with a mosaic of proteins

• In a single layer of lipids

• In a crystalline lattice

What is the effect of cholesterol on membrane fluidity at high temperatures?

• Increases fluidity by allowing more movement

• Decreases fluidity by restraining phospholipid movement

• Has no effect on fluidity

• Increases fluidity by breaking down lipids

What happens to a membrane when it solidifies?

• It becomes more permeable

• Its permeability remains unchanged

• Its permeability decreases

• It becomes more fluid

How does the lateral movement of phospholipids within the membrane occur?

• Very slowly, about 1 um per second

• Rapidly, about 2 um per second

• Not at all, they are immobile

• Only when temperature decreases

What type of phospholipids helps a membrane remain fluid at lower temperatures?

• Saturated phospholipids

• Phospholipids with unsaturated hydrocarbon tails

• Phospholipids with saturated hydrocarbon tails

• Phospholipids with no hydrocarbon tails

What is the main fabric of the plasma membrane composed of?

• Carbohydrates

• Phospholipids

• Nucleic acids

• Sugars