Question 1: The particle model describes matter as being made up of tiny particles that are in constant motion. In biological systems, this model helps explain how substances like gases and liquids diffuse through tissues and cells. Understanding this concept is crucial for medical applications such as drug delivery and respiratory function.

Answer: The particle model explains matter as tiny particles in constant motion, which helps explain diffusion, osmosis, and other processes important in medicine.

Question 1: Define diffusion in terms of the particle model.

Answer: Diffusion is the movement of particles from a region of higher concentration to a region of lower concentration, due to their constant random motion.

Question 2: Explain why gases diffuse faster than liquids according to the particle model.

Answer: Gases diffuse faster because their particles are farther apart and move more rapidly than in liquids.

Question 1: Calculate the average kinetic energy (in joules) of nitrogen molecules (N₂) at body temperature 37°C. Use the formula: KE = (3/2) k T, where k = 1.38 x 10⁻²³ J/K and T is in kelvin.

Answer: KE = (3/2) × 1.38×10⁻²³ × (37 + 273) = 8.55×10⁻²³ Joules

Question 1: Design a simple experiment to demonstrate how temperature affects the rate of diffusion of a dye in a biological fluid. Identify the variables involved and the safety precautions that should be taken.

Answer: An experiment can involve placing a dye in a sample of biological fluid (e.g., blood plasma) at different temperatures and measuring the time taken for the dye to diffuse a certain distance. Variables include temperature (independent), diffusion rate (dependent), and concentration of dye (controlled). Safety precautions include wearing gloves, eye protection, and working in a well-ventilated area.

Question 1: A patient with a respiratory condition inhales a gas mixture. The partial pressure of oxygen in the alveoli is 13 kPa, while in the blood it is 5 kPa. Using the particle model, explain why oxygen diffuses into the blood.

Answer: Oxygen diffuses into the blood because its partial pressure is higher in the alveoli than in the blood, causing particles to move from high to low pressure areas, consistent with the particle model.

Question 1: Describe how the particle model is used to improve targeted drug delivery systems in medicine.

Answer: The particle model helps in designing drug particles that can diffuse effectively through cell membranes, ensuring targeted delivery by controlling particle size, charge, and solubility for optimal diffusion and absorption.

Question 1: Explain how the particle model accounts for the process of osmosis in biological systems, including the role of particle movement and concentration gradients. Your answer should include relevant scientific principles and real-world implications in medicine.

Answer: Osmosis is the movement of water particles from a region of lower solute concentration to a higher solute concentration across a semi-permeable membrane. According to the particle model, water particles move due to random motion, driven by the concentration gradient. This process is vital in maintaining cell hydration and function. In medicine, understanding osmosis helps in managing intravenous fluids and treating oedema.