Exploring Cell Membrane Dynamics

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

• The hydrophobic tails attract water, forming a single layer.

• The hydrophilic heads face outward, interacting with water, while the hydrophobic tails face inward, away from water, forming a bilayer.

• The hydrophilic heads repel water, forming a solid barrier.

• The hydrophobic tails face outward, interacting with water, while the hydrophilic heads face inward, away from water.

Analyze the role of cholesterol in maintaining the fluidity of the cell membrane at different temperatures.

• Cholesterol decreases membrane fluidity at high temperatures and increases it at low temperatures.

• Cholesterol increases membrane fluidity at high temperatures and decreases it at low temperatures.

• Cholesterol has no effect on membrane fluidity.

• Cholesterol only affects membrane fluidity at high temperatures.

Evaluate the importance of integral membrane proteins in cell signaling.

• Integral membrane proteins are not involved in cell signaling.

• Integral membrane proteins act as channels for ions only.

• Integral membrane proteins serve as receptors that transmit signals from the extracellular environment to the cell's interior.

• Integral membrane proteins only provide structural support to the membrane.

Discuss how the structure of the phospholipid bilayer affects the permeability of the cell membrane.

• The bilayer allows all molecules to pass freely.

• The bilayer is impermeable to all substances.

• The bilayer is selectively permeable, allowing small nonpolar molecules to pass while restricting large polar molecules.

• The bilayer allows only water molecules to pass.

Compare and contrast facilitated diffusion and active transport in terms of energy requirements and direction of movement.

• Both require energy and move substances against their concentration gradient.

• Facilitated diffusion requires energy, while active transport does not.

• Facilitated diffusion does not require energy and moves substances down their concentration gradient, while active transport requires energy and moves substances against their concentration gradient.

• Both do not require energy and move substances down their concentration gradient.

Design an experiment to demonstrate the process of osmosis using a semi-permeable membrane and a sugar solution.

• Use a beaker of water and a balloon.

• Use a dialysis bag filled with sugar solution placed in a beaker of water, and measure the change in mass of the bag over time.

• Use a beaker of sugar solution and a piece of paper.

• Use a beaker of water and a metal rod.

Critically assess the impact of temperature on the rate of diffusion across a cell membrane.

• Temperature has no effect on the rate of diffusion.

• Higher temperatures decrease the rate of diffusion.

• Higher temperatures increase the rate of diffusion by providing more kinetic energy to molecules.

• Lower temperatures increase the rate of diffusion.

Explain how the sodium-potassium pump functions as an example of active transport.

• It moves sodium and potassium ions down their concentration gradients without using energy.

• It uses ATP to move sodium ions out of the cell and potassium ions into the cell against their concentration gradients.

• It allows sodium and potassium ions to move freely across the membrane.

• It only moves sodium ions into the cell.

Analyze the role of aquaporins in the process of osmosis.

• Aquaporins block water from passing through the membrane.

• Aquaporins facilitate the rapid transport of water molecules across the cell membrane.

• Aquaporins transport ions across the membrane.

• Aquaporins are involved in active transport of water.

Tags

NGSS.HS-LS1-3

Evaluate the effects of hypotonic, isotonic, and hypertonic solutions on animal cells.

• Hypotonic solutions cause cells to shrink, isotonic solutions cause cells to swell, and hypertonic solutions have no effect.

• Hypotonic solutions cause cells to swell, isotonic solutions maintain cell size, and hypertonic solutions cause cells to shrink.

• All solutions cause cells to swell.

• All solutions cause cells to shrink.