Exploring Membrane Transport Mechanisms

Which of the following is a characteristic of passive transport?

• Requires ATP to function

• Moves substances against their concentration gradient

• Moves substances down their concentration gradient

• Involves vesicle formation

What is the role of cholesterol in the cell membrane?

• It acts as a channel for ions.

• It provides rigidity and stability to the membrane.

• It synthesizes proteins.

• It stores genetic information.

Which of the following processes is an example of active transport?

• Osmosis

• Facilitated diffusion

• Sodium-potassium pump

• Simple diffusion

Explain how the amphipathic nature of phospholipids contributes to the formation of the cell membrane.

• The hydrophilic heads and hydrophobic tails form a bilayer that is impermeable to all substances.

• The hydrophilic heads face outward, and the hydrophobic tails face inward, creating a semi-permeable membrane.

• The hydrophobic tails face outward, allowing water to pass freely.

• The hydrophilic heads face inward, repelling all substances.

Describe how ion channels facilitate the movement of ions across the cell membrane.

• Ion channels actively transport ions against their concentration gradient.

• Ion channels allow ions to passively diffuse across the membrane.

• Ion channels are involved in endocytosis.

• Ion channels synthesize ATP.

Compare and contrast the processes of endocytosis and exocytosis.

• Both processes involve the passive transport of molecules.

• Endocytosis involves the intake of materials, while exocytosis involves the expulsion of materials.

• Endocytosis requires energy, while exocytosis does not.

• Both processes are forms of passive transport.

Predict the effect on a cell if it is placed in a hypotonic solution and justify your prediction.

• The cell will shrink because water will move out of the cell.

• The cell will swell and possibly burst because water will move into the cell.

• The cell will remain the same size because there is no net movement of water.

• The cell will become rigid due to the high solute concentration inside.

Tags

NGSS.HS-LS1-3

Analyze the role of the sodium-potassium pump in maintaining cellular homeostasis.

• It allows sodium ions to passively diffuse into the cell.

• It actively transports sodium ions out and potassium ions into the cell, maintaining a negative charge inside.

• It passively transports potassium ions out of the cell.

• It allows potassium ions to passively diffuse into the cell.

Tags

NGSS.HS-LS1-3

Which of the following best describes facilitated diffusion?

• Movement of molecules against their concentration gradient with the help of ATP.

• Movement of molecules down their concentration gradient with the help of transport proteins.

• Movement of water molecules through a semi-permeable membrane.

• Movement of molecules through the lipid bilayer without any assistance.

What is the primary role of ATP in active transport mechanisms?

• ATP provides the energy needed to move substances against their concentration gradient.

• ATP acts as a channel for ions to pass through the membrane.

• ATP is used to synthesize proteins in the cell.

• ATP is a waste product of active transport.