1.3ai Membrane Structure

What is the primary structure of the plasma membrane described by the fluid mosaic model?

• A single layer of phospholipids

• A bilayer of phospholipid molecules

• A layer of carbohydrates

• A rigid structure of proteins

What characteristic does the head region of a phospholipid molecule have?

• Non-polar and hydrophobic

• Charged and hydrophilic

• Neutral and hydrophobic

• Uncharged and hydrophobic

What is the nature of the tail region of a phospholipid molecule?

• Charged and polar

• Polar and hydrophilic

• Uncharged and non-polar

• Charged and hydrophilic

What quality does the constant movement of phospholipids give to the membrane?

• Static quality

• Fluid quality

• Rigid quality

• Solid quality

What forms the 'mosaic' part of the fluid mosaic model?

• Carbohydrates

• Lipids

• Proteins

• Nucleic acids

How are integral membrane proteins held in place within the membrane?

• By ionic bonds with phospholipid heads

• By covalent bonds with carbohydrates

• By hydrogen bonds with water molecules

• By hydrophobic interactions with phospholipid tails

What type of proteins span the entire width of the membrane?

• Surface proteins

• Transmembrane proteins

• Integral proteins

• Peripheral proteins

What type of interactions hold peripheral membrane proteins to the membrane?

• Hydrophobic interactions

• Ionic and hydrogen bond interactions

• Covalent bonds

• Van der Waals forces

What type of R groups do peripheral membrane proteins have on their surface?

• Hydrophobic R groups

• Hydrophilic R groups

• Non-polar R groups

• Neutral R groups

What is the main role of the phospholipid bilayer in the cell membrane?

• To store energy

• To synthesize proteins

• To provide a barrier

• To conduct nerve impulses