Because the molecules in food are too large and insoluble to move through cell membranes E.g. epithelial cell membranes lining the ileum and so need to be broken down into smaller, more soluble molecules
What is physical digestion?
Breaking large pieces of food into smaller pieces. Doesn't break any chemical bonds
Where does physical digestion take place?
Mouth, using the tongue and teeth to chew food
Stomach, which churns food
Small intestine, which emulsifies lipids using bile
Define hydrolysis.
The breaking of a chemical bond using water
Write a word equation that describes chemical digestion.
Polymers of large molecules --->(hydrolysis & enzymes) monomers or small molecules
What are epithelial cells?
Cells that form a barrier between internal and external environments
Define lumen.
The space inside tubes in biology E.g. in veins, arteries, ileum
What is the ileum?
The small intestine
What is digestion?
Process where large insoluble biological molecules are hydrolysed into smaller soluble molecules
