DigestionAQA A-Level Biology: Flashcards

What these 13 flashcards ask

Why must large molecules be digested before absorption?
What is hydrolysis?
What does amylase do?
Where is amylase produced?
What are membrane-bound disaccharidases?
Name the products of maltase, sucrase and lactase.
What does lipase do?
What are bile salts and what do they do?
Why does emulsification speed up lipid digestion?
What do endopeptidases do?
What do exopeptidases do?
What do membrane-bound dipeptidases do?
Why do endopeptidases increase the rate of exopeptidase action?

Exam questions on Digestion

A person eats a meal of bread, which is rich in starch. The starch is digested during passage through the gut and the products are absorbed across the epithelium of the small intestine.
Explain why the maltose formed from starch must be hydrolysed further before it can be absorbed.2 marks
A person eats a meal containing a large amount of fat. The fat is digested in the small intestine by lipase from the pancreas, with the help of bile, which is made in the liver, stored in the gall bladder and released into the small intestine.
Explain how bile salts increase the rate of digestion of the fat.2 marks
Proteins in food are digested in the stomach and the small intestine by a series of enzymes. A dietary protein contains a single polypeptide chain of 90 amino acids.
Describe the roles of endopeptidases, exopeptidases and membrane-bound dipeptidases in the digestion of the protein.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).