Cell Membrane Structure and Function

This video tutorial covers the structure and function of the cell membrane, focusing on the fluid mosaic model. It explains the roles of phospholipids, proteins, glycoproteins, glycolipids, and cholesterol in maintaining membrane integrity and function. The video also discusses transport mechanisms, including diffusion and the role of aquaporins and ion channels. Finally, it provides practice problems to reinforce the concepts covered.

What does the fluid mosaic model suggest about the cell membrane?

• It is rigid and static.

• It is composed of a single type of molecule.

• It is impermeable to all substances.

• It is fluid and composed of various components.

Which part of a phospholipid is hydrophilic?

• The entire molecule

• The fatty acid tails

• The phosphate head

• The glycerol backbone

What term describes a molecule with both hydrophilic and hydrophobic parts?

• Amphipathic

• Hydrophilic

• Polar

• Hydrophobic

Which type of protein spans the entire cell membrane?

• Peripheral protein

• Surface protein

• Globular protein

• Transmembrane protein

What is the role of aquaporins in the cell membrane?

• Transport glucose

• Transport water

• Transport ions

• Transport proteins

Which molecules can easily diffuse through the cell membrane without assistance?

• Small nonpolar molecules

• Ions

• Large polar molecules

• Proteins

What is the function of cholesterol in the cell membrane?

• To transport molecules

• To increase membrane permeability

• To maintain membrane fluidity

• To make the membrane more rigid

How does increasing temperature affect the fluidity of the cell membrane?

• Decreases fluidity

• Solidifies the membrane

• Has no effect

• Increases fluidity

Which of the following cannot pass through the cell membrane without a transport protein?

• Water

• Oxygen

• Carbon dioxide

• Potassium ions

What type of fatty acids increase the fluidity of the cell membrane?

• Trans fatty acids

• Unsaturated fatty acids

• Hydrogenated fatty acids

• Saturated fatty acids