IGCSEBiologyCambridge (CIE)Revision Notes7. Human NutritionHuman Diet & DigestionBile

Bile (Cambridge (CIE) IGCSE Biology): Revision Note

Exam code: 0610 & 0970

Written by: Lára Marie McIvor

Reviewed by: Jenna Quinn

Updated on 25 August 2026

Bile: Extended

Extended Tier Only

Cells in the liver produce bile which is then stored in the gallbladder

Diagram of liver, gall bladder, pancreas and duodenum showing bile production, storage and flow through hepatic and bile ducts, and enzymes via pancreatic duct — **Bile production and secretion**

Bile has two main roles:
- It is alkaline to neutralise the hydrochloric acid which comes from the stomach
  - The enzymes in the small intestine have a higher (more alkaline) optimum pH than those in the stomach
- It breaks down large drops of fat into smaller ones. This is known as emulsification. The larger surface area allows lipase to chemically break down the lipid into glycerol and fatty acids faster

Examiner Tips and Tricks

Emulsification is the equivalent of tearing a large piece of paper into smaller pieces of paper. This is an example of mechanical digestion, not chemical digestion – breaking something into smaller pieces does not break bonds or change the chemical structure of the molecules which make it up, which is the definition of chemical digestion. Make sure you're clear on the distinction.

Unlock more, it's free!

Join the 100,000+ Students that ❤️ Save My Exams

the (exam) results speak for themselves:

I would just like to say a massive thank you for putting together such a brilliant, easy to use website.I really think using this site helped me secure my top gradesin science and maths. You really did save my exams! Thank you.

Beth
IGCSE Student

This website is soooo useful and I can’t ever thank you enough for organising questions by topic like this. Furthermore, the name of the website could not have been more appropriate as it literally did SAVE MY EXAMS!

Fathima
A Level Student

Incredible! SO worth my money, the revision notes have everything I need to know and are so easy to understand. I actually enjoy revising! It makes me feel a lot more confident for my GCSEs in a few months.

Kate
GCSE Student

Absolutely brilliant, both my girls used it for A levels and GCSE. It's saves on paper copies, also beneficial exam questions ranked from easy to hard. It's removed a lot of stress from the exams.

Sameera
Parent

Just to say that your resources are the best I have seen and I have been teaching chemistry at different levels for about 40 years

Mark
Chemistry Teacher

Excellent