Digestion Flashcards
Why does food have to be digested?
Some food molecules are too big to be absorbed through the gut and into the blood so they must be broken down before it can be absorbed.
How are carbohydrates broken down?
Amylase breaks down starch into maltose. Then maltase breaks down maltose into glucose.
Where is amylase produced?
It is produced in the salivary glands and released into the mouth. It is also produced in the pancreas and is released into the small intestine.
What are membrane-bound disaccharidases?
Enzymes attached to the cell membranes of epithelial cells lining the ileum break down disaccharides into monosaccharides by hydrolysing glycosidic bonds.
How are lipids broken down?
Lipase breaks lipids into monoglycerides and fatty acids by hydrolyzing ester bonds.
Where is lipase made?
Made in the pancreas and secreted into the small intestine.
What is the role of bile in the digestion of lipids?
It emulsifies the lipids which increases their surface area making them easier to break down.
How are micelles formed in digestion what is their role in the absorption of lipids?
The monoglycerides and fatty acids stick with the bile salts to make micelles. The micelles make it easier for the lipids to be absorbed.
How are proteins broken down?
Endopeptidases break down peptide bonds within a polypeptide to make smaller peptidases. Exopeptidases break down peptide bonds at the end of the polypeptides to release amino acids. Dipeptidases break down peptides into amino acids.
Where are peptidases made?
- In the stomach
- Made in the pancreas and secreted into the small intestine.
- Dipeptidases are found on the membrane of the epithelial cells in the ileum.
How are monosaccharides absorbed across the ileum?
Glucose are galactose are absorbed across the ileum via co-transport and fructose via facilitated diffusion.
How are amino acids absorbed across the ileum?
co-transport
How are monoglycerides and fatty acids absorbed across the ileum?
Micelles release them at the membrane and they diffuse across it because they are lipid soluble.
