Question 1: Define diffusion in the context of cell biology.

Answer: Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Question 2: Explain why diffusion is an important process for cells.

Answer: Diffusion allows essential substances like oxygen and nutrients to enter cells and waste products to exit, maintaining proper cell function.

Question 3: Identify the main driving force behind diffusion.

Answer: Concentration gradient, which is the difference in particle concentration between two areas.

Question 1: Calculate the rate of diffusion if 150 particles move across a membrane in 30 seconds. Express your answer in particles per second.

Answer: Rate = 150 particles / 30 seconds = 5 particles per second

Question 2: If the concentration of particles is doubled on one side of a membrane, how does this affect the rate of diffusion? Explain your reasoning.

Answer: Doubling the concentration increases the concentration gradient, which generally increases the rate of diffusion because more particles move from high to low concentration.

Question 1: Describe a simple experiment to demonstrate diffusion using a food coloring and water. Include the variables involved and safety precautions.

Answer: A common experiment involves placing a few drops of food coloring in a glass of water and observing how the color spreads evenly throughout the water over time. Variables include the amount of food coloring, water temperature, and water volume. Safety precautions include handling food coloring carefully to avoid staining and ensuring the water is clean to prevent contamination.

Question 2: Why is diffusion faster at higher temperatures? Provide a scientific explanation.

Answer: Higher temperatures increase particle energy, causing particles to move faster, which speeds up the process of diffusion.

Question 1: In an experiment, the concentration of a gas outside a cell membrane is 80 units, and inside the cell, it is 20 units. Over 10 minutes, 600 particles moved from outside to inside. What can you infer about the direction of diffusion and the concentration gradient?

Answer: Particles moved from outside to inside, indicating diffusion from high to low concentration. The concentration gradient was from 80 units outside to 20 units inside, driving the movement.

Question 2: If the rate of diffusion slows down over time in an experiment, what could be the possible reasons?

Answer: Possible reasons include reaching equilibrium where concentration differences are minimal, temperature decrease reducing particle movement, or the membrane becoming less permeable.

Question 1: Explain how diffusion is involved in the process of oxygen entering the lungs during respiration.

Answer: Oxygen diffuses from the alveoli in the lungs, where its concentration is high, into the blood, where its concentration is lower, enabling gas exchange.

Question 2: Describe one industrial application that uses diffusion principles to improve product quality or process efficiency.

Answer: In water purification, diffusion is used in membrane filtration systems to remove impurities from water by allowing only certain molecules to pass through membranes based on size and concentration.