AQA GCSE Biology Paper 1 Practice Exam 2025 – Complete Study Guide

Fat emulsification during digestion is primarily accomplished by bile produced in the liver. Bile contains bile salts which act like detergents, breaking larger fat globules down into much smaller droplets. This process increases the surface area of the fat, making it easier for digestive enzymes, specifically lipases, to access and break down the fat molecules into fatty acids and glycerol.

Bile is stored in the gallbladder and released into the small intestine where it plays a crucial role in the digestion of fats. Without the action of bile, fat digestion would be inefficient, as larger droplets are more challenging for enzymes to process effectively. Therefore, the involvement of bile in emulsifying fats is a key part of the digestive process, highlighting the importance of this substance in maintaining proper nutritional absorption.