Biology 101 Chapter 5

What is the primary function of the plasma membrane?

• To store genetic information

• To separate internal cytoplasm from the external environment

• To produce energy for the cell

• To synthesize proteins

Which model accounts for the structure of the plasma membrane?

• Lock and key model

• Fluid mosaic model

• Double helix model

• Induced fit model

What lines the external surface of the phospholipid bilayer?

• Hydrophobic polar heads

• Hydrophilic polar heads

• Nonpolar fatty-acid tails

• Integral proteins

Which component of the plasma membrane affects its fluidity?

• Phospholipid bilayer

• Protein molecules

• Cholesterol

• Carbohydrates

What is the role of integral proteins in the plasma membrane?

• They are found only on the outer membrane surface

• They are partially or wholly embedded in the membrane

• They store energy for the cell

• They synthesize lipids

What does the fluid mosaic model describe?

• The structure of the cell membrane as a static, rigid structure.

• The structure of the cell membrane as a dynamic, flexible structure.

• The structure of the cell wall as a dynamic, flexible structure.

• The structure of the nucleus as a static, rigid structure.

What role do glycoproteins and glycolipids play in cells?

• They contribute to the cell's energy production.

• They contribute to the cell's 'fingerprint' and play a role in cellular identification.

• They contribute to the cell's structural integrity.

• They contribute to the cell's waste removal.

What is the primary function of channel proteins?

• Bind with specific molecules

• Allow passage of molecules through membrane via a channel

• Carry out metabolic reactions directly

• Attach adjacent cells

Which type of protein helps the body recognize foreign substances?

• Channel proteins

• Carrier proteins

• Cell recognition proteins

• Junction proteins

What is the role of receptor proteins?

• Assist passage of molecules through membrane

• Bind with specific molecules and allow a cell to respond to signals

• Carry out metabolic reactions directly

• Attach adjacent cells