S25 BIO - Unit 2: Checkpoint Cell Membranes

What is the main component of the cell membrane that forms a bilayer?

• Proteins

• Phospholipids

• Carbohydrates

• Nucleic acids

Which model describes the structure of the cell membrane as a flexible layer made of lipid molecules and interspersed with proteins?

• Lock and Key Model

• Fluid Mosaic Model

• Double Helix Model

• Sandwich Model

Why the cell membrane is described as "semipermeable"?

• It allows all substances to pass through.

• It allows only water to pass through.

• It allows some substances to pass while blocking others.

• It blocks all substances from passing through.

How do phospholipids arrange themselves in the cell membrane?

• In a single layer with heads facing outwards

• In a bilayer with heads facing outwards and tails facing inwards

• In a bilayer with tails facing outwards and heads facing inwards

• In a single layer with tails facing outwards

What role do proteins play in the cell membrane?

• They provide energy for the cell.

• They help in the transport of substances across the membrane.

• They store genetic information.

• They make the membrane rigid.

Tags

NGSS.HS-LS1-1

How does the fluid mosaic model explain the movement of proteins within the cell membrane?

• Proteins are fixed in place and do not move.

• Proteins can move laterally within the lipid bilayer.

• Proteins move vertically through the membrane.

• Proteins are only found on the outer surface of the membrane.

Why is the cell membrane important for protecting the cell?

• It provides a rigid structure to the cell.

• It acts as a barrier to harmful substances.

• It allows all substances to enter the cell.

• It stores nutrients for the cell.

Tags

NGSS.MS-LS1-2

How does the structure of phospholipids contribute to the semipermeability of the cell membrane?

• The hydrophilic heads repel water, preventing passage.

• The hydrophobic tails attract water, allowing passage.

• The hydrophilic heads and hydrophobic tails create a selective barrier.

• The hydrophobic tails form a solid barrier that blocks all substances.

What might happen if the cell membrane lost its semipermeability?

• The cell would become more efficient at nutrient uptake.

• The cell would be unable to maintain homeostasis.

• The cell would become impermeable to all substances.

• The cell would only allow water to pass through.

Tags

NGSS.HS-LS1-3

What is the importance of membrane proteins in cell communication?

• Membrane proteins have no role in cell communication.

• Membrane proteins are only involved in structural support.

• Membrane proteins are crucial for receiving and transmitting signals.

• Membrane proteins only help in energy production.