Practise tracing starch, protein and fat digestion through named enzymes, products and gut locations, then connect pH conditions and solubility to nutrient absorption.
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
Cells in the lining of the stomach secrete gastric juice, which contains hydrochloric acid and pepsin.
State two roles of hydrochloric acid in the stomach.
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2
Describe the function of pepsin.
Starch and sucrose are made by plants after photosynthesis.
Describe how starch is broken down in the human digestive system so that it can be absorbed into the blood.