Cell Membranes

Mr. Anderson introduces the concept of cell membranes, explaining selective permeability and the fluid mosaic model. He discusses the roles of phospholipids, proteins, cholesterol, glycoproteins, and glycolipids in the cell membrane. The video also covers the structure and function of cell walls in plants, bacteria, and fungi, highlighting their importance in providing rigidity and protection.

What is the primary reason soap can dissolve cell membranes during DNA extraction?

• Soap is alkaline and neutralizes acids.

• Soap is made of lipids, similar to cell membranes.

• Soap is acidic and breaks down proteins.

• Soap contains enzymes that digest DNA.

What does selective permeability of a cell membrane mean?

• It blocks all substances from entering.

• It only allows water to pass through.

• It allows all substances to pass through.

• It regulates what enters and exits the cell.

Which model describes the structure of the cell membrane?

• Static Layer Model

• Rigid Framework Model

• Fluid Mosaic Model

• Solid State Model

What role does cholesterol play in the cell membrane?

• It acts as a receptor for hormones.

• It blocks protein channels.

• It dissolves the membrane.

• It connects and stabilizes phospholipids.

What are glycoproteins primarily involved in?

• Immune response

• DNA replication

• Protein synthesis

• Energy production

What is the unique feature of phospholipids in the cell membrane?

• They are rigid and immobile.

• They are entirely hydrophobic.

• They are entirely hydrophilic.

• They have a hydrophilic head and hydrophobic tail.

How do proteins assist in the transport across the cell membrane?

• They facilitate the movement of large or charged molecules.

• They form rigid barriers.

• They dissolve in water.

• They block all molecules from passing.

What is the function of aquaporins in the cell membrane?

• They synthesize proteins.

• They block ions from entering.

• They transport glucose.

• They allow water to pass through.

What is the primary component of plant cell walls?

• Peptidoglycan

• Chitin

• Lignin

• Cellulose

Which organisms have cell walls made of chitin?

• Fungi

• Plants

• Bacteria

• Animals