Electrically Active Cell Membranes OS 12.4.1 cfu quiz

Which type of particles do most cells in the body use to build up a charge across the cell membrane?

• Uncharged molecules

• Water molecules

• Charged particles (ions)

• Proteins

What is the primary function of the cell membrane in relation to charged particles?

• To produce energy for the cell

• To regulate what can cross the membrane and what stays on only one side

• To store genetic information

• To synthesize proteins

Which protein is responsible for moving sodium ions out of a cell and potassium ions into a cell?

• Calcium channel

• Sodium/potassium pump

• Glucose transporter

• Aquaporin

Tags

NGSS.HS-LS1-3

Explain how the sodium/potassium pump maintains concentration gradients of Na⁺ and K⁺ across the cell membrane.

• By allowing ions to move freely across the membrane

• By moving Na⁺ and K⁺ ions with their concentration gradients

• By using energy to move Na⁺ out and K⁺ in against their concentration gradients

• By synthesizing new ions inside the cell

Tags

NGSS.HS-LS1-3

What is the main characteristic of a ligand-gated channel?

• It opens in response to a signaling molecule binding to it

• It opens due to physical distortion of the membrane

• It opens randomly without any specific trigger

• It opens in response to changes in temperature

Which type of ion channel opens due to a physical distortion of the cell membrane?

• Mechanically gated channel

• Voltage-gated channel

• Ligand-gated channel

• Leakage channel

Explain how a voltage-gated channel operates and what triggers its opening.

• It opens in response to changes in the electrical properties of the membrane, specifically when the inner portion becomes less negative.

• It opens when a ligand binds to the extracellular region.

• It opens due to random switching between open and closed states.

• It opens when the membrane is physically distorted.

A leakage channel is best described as:

• A channel that opens and closes at random, contributing to the resting transmembrane voltage.

• A channel that opens only when a neurotransmitter binds to it.

• A channel that opens in response to temperature changes.

• A channel that is always closed unless physically forced open.

Identify the Concentration Gradient

a

b

Low Concentration

High Concentration