Cell Permeability

This video by Mr. Andersen covers the cell membrane, explaining its structure and function. It begins with a demonstration of DNA extraction from a banana, highlighting the role of cell membranes. The video delves into selective permeability and the fluid mosaic model, describing how phospholipids and proteins regulate transport across the membrane. It also discusses the importance of cholesterol, glycoproteins, and glycolipids. The video concludes with a comparison of cell walls in plants, bacteria, and fungi, emphasizing their structural roles.

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

• Soap is acidic and breaks down proteins.

• Soap reacts with DNA to make it visible.

• Soap is basic and neutralizes the cell's pH.

• Soap dissolves lipids, which are a major component of cell membranes.

What does selective permeability of a cell membrane mean?

• It allows all substances to pass through freely.

• It blocks all substances from entering the cell.

• It only allows water to pass through.

• It regulates the entry and exit of certain substances.

Which model describes the structure of the cell membrane?

• Static Lipid Model

• Rigid Framework Model

• Fluid Mosaic Model

• Solid State Model

What role does cholesterol play in the cell membrane?

• It connects phospholipids and maintains membrane fluidity.

• It acts as a barrier to all substances.

• It dissolves proteins in the membrane.

• It provides energy for cell processes.

What are glycoproteins primarily involved in?

• DNA replication

• Protein synthesis

• Immune response

• Energy production

What is the unique feature of phospholipids that contributes to membrane structure?

• They have a hydrophilic head and a hydrophobic tail.

• They are entirely hydrophobic.

• They are completely hydrophilic.

• They are rigid and immobile.

How do small, non-charged particles like oxygen move across the cell membrane?

• Through active transport

• By facilitated diffusion

• Via endocytosis

• By simple diffusion

What is the function of aquaporins in the cell membrane?

• They allow water to pass through the membrane.

• They block ions from entering the cell.

• They synthesize proteins.

• They transport glucose across the membrane.

What is the primary component of plant cell walls?

• Lignin

• Cellulose

• Peptidoglycan

• Chitin

Which organisms have cell walls made of peptidoglycan?

• Plants

• Animals

• Fungi

• Bacteria