Practise tracing starch, protein and fat digestion through named enzymes, products and gut locations, then connect pH conditions and solubility to nutrient absorption.
Fig. 1.1 shows the movement of particles through an epithelial cell in the small intestine.
Fig. 1.1
In Fig. 1.1, particle R moves from the lumen of the small intestine into the epithelial cell.
Suggest why particle R cannot be starch.
Describe the role of chemical digestion.
Maltose is digested by maltase.
State the name of the product of this reaction.
Describe where maltose is digested in the small intestine.
Tissue plasminogen activators (TPAs) are human proteins that are used as drugs to break down blood clots.
TPAs break down blood clots by activating plasminogen. Plasminogen is a protein that is always present in the blood.
When activated, plasminogen forms a protease that breaks down fibrin molecules.
State the products of the action of protease on the protein fibrin.
TPAs can be produced by genetically-engineered bacteria.
Fig. 5.1 shows some of the stages involved in genetically engineering a bacterium to make a TPA.
Fig. 5.1