5.1 Understanding the Plasma Membrane

What is the primary function of the plasma membrane in a cell?

• To provide structural support

• To regulate the movement of substances in and out of the cell

• To store genetic information

• To produce energy

Which term describes the plasma membrane's ability to allow certain substances to pass while blocking others?

• Hydrophilic

• Selectively permeable

• Hydrophobic

• Phospholipid bilayer

What is the structural composition of the plasma membrane?

• Protein monolayer

• Carbohydrate layer

• Phospholipid bilayer

• Nucleic acid layer

In a phospholipid molecule, what is the characteristic of the phosphate head?

• Hydrophobic

• Hydrophilic

• Non-polar

• Neutral

What is the characteristic of the fatty acid tails in a phospholipid molecule?

• Hydrophilic

• Polar

• Hydrophobic

• Charged

Which part of the phospholipid molecule is attracted to water?

• Fatty acid tail

• Phosphate head

• Lipid core

• Protein channel

Which part of the phospholipid molecule repels water?

• Phosphate head

• Fatty acid tail

• Protein channel

• Carbohydrate chain

What is the role of the phospholipid bilayer in the plasma membrane?

• To provide energy for the cell

• To act as a barrier to most water-soluble substances

• To store genetic information

• To synthesize proteins

Which of the following best describes the arrangement of phospholipids in the plasma membrane?

• Randomly scattered

• Single layer

• Double layer with heads facing outward

• Triple layer with tails facing outward

What property of the plasma membrane allows it to self-repair if punctured?

• Its rigid structure

• Its hydrophilic nature

• Its fluid mosaic model

• Its carbohydrate content