Question 1: Define bile and describe its primary function in the digestive system.

Answer: Bile is a digestive fluid produced by the liver that helps break down fats by emulsification, making them easier to digest.

Question 2: Explain how bile aids in the digestion of lipids.

Answer: Bile contains bile salts that emulsify large fat globules into smaller droplets, increasing the surface area for enzymes like lipase to act upon.

Question 1: The liver produces approximately 600 mL of bile daily. If bile contains 4% bile salts by volume, calculate the volume of bile salts produced in a day. (Show your working.)

Answer: 24 mL. Calculation: 600 mL × 0.04 = 24 mL.

Question 2: A person consumes 50 grams of fat in a meal. If the average emulsification process reduces fat droplet size by 70%, estimate the new average droplet size assuming initial droplets are 20 micrometers. (Use proportional reasoning; show your work.)

Answer: 6 micrometers. Calculation: 20 μm × (1 - 0.70) = 6 μm.

Question 1: Describe a simple experimental setup to study the effect of bile salts on fat digestion in a laboratory setting. Include variables to control and safety precautions.

Answer: An experiment could involve two solutions: one with bile salts and one without. Add equal amounts of fat to each solution, maintain constant temperature, pH, and sample at intervals. Variables to control include temperature and pH; safety precautions include handling fats and chemicals carefully and disposing of waste properly.

Question 2: Identify the independent variable, dependent variable, and one control variable in the experiment described above.

Answer: Independent variable: Presence of bile salts; Dependent variable: Rate of fat digestion; Control variable: Temperature.

Question 1: A study shows that after consuming a high-fat meal, bile concentration in the gall bladder increases by 30% within 2 hours. Explain the biological significance of this change.

Answer: The increase in bile concentration helps to emulsify the larger amount of fats ingested, facilitating their digestion and absorption in the small intestine.

Question 1: Describe how a deficiency in bile production could affect digestion and nutrient absorption.

Answer: A deficiency in bile production would impair emulsification of fats, leading to poor fat digestion and absorption. This can result in fatty stools (steatorrhoea), deficiencies in fat-soluble vitamins (A, D, E, K), and overall nutritional deficiencies.

Question 2: Bile salts are increasingly used in the food industry as additives. Explain their role and any potential health considerations associated with their use.

Answer: Bile salts are used as emulsifiers to improve texture and stability of processed foods. However, excessive intake may cause gastrointestinal discomfort or interfere with natural fat digestion, and their use must adhere to food safety regulations to prevent adverse health effects.