3.3 Digestion and absorption Flashcards
What is digestion?
The chemical or mechanical process where large molecules are hydrolysed into small, soluble molecules that can be absorbed across the cell membrane, and into the bloodstream.
What does amylase do?
Hydrolyses starch into maltose.
How does amylase hydrolyse starch into maltose?
By hydrolysing the glycosidic bonds.
What does maltase do?
Hydrolyses maltose into glucose.
What is maltase?
Membrane-bound disaccharidase.
How does maltase hydrolyse maltose into glucose?
By hydrolysing the glycosidic bonds.
What does sucrase do?
Hydrolyses sucrose into glucose and fructose.
What does lactase do?
Hydrolyses lactose into glucose and galactose.
Where can starch be broken down?
In the mouth and small intestine.
Where is amylase released from?
From the mouth and pancreas.
What enzyme digests proteins in the stomach?
Endopeptidases.
What do endopeptidases do?
Hydrolyse peptide bonds within an amino acid chain.
What is the purpose of endopeptidases?
Increase surface area.
What enzymes break down proteins in the duodenum?
Endopeptidases, exopeptidases, and dipeptidases.
What do exopeptidases do in the duodenum?
Hydrolyse peptide bonds at the end of the amino acid chain.
What do dipeptidases do in the duodenum?
Hydrolyse peptide bonds between 2 amino acids (dipeptides).
What is a triglyceride?
Glycerol and 3 fatty acids.
What does lipase do?
Hydrolyses the ester bond in triglycerides to form monoglycerides and fatty acids.
Where are bile salts formed?
In the liver.
Where are bile salts stored?
In the gall bladder.
Where are bile salts released?
Into the bile duct.
What do bile salts do?
Emulsify lipids.
What do bile salts emulsify lipids into?
Large droplets into small droplets.
Why is it useful that bile salts emulsify lipids into smaller droplets?
Provides a larger surface area for faster hydrolysis and more enzyme-substrate complexes formed.