Practise tracing starch, protein and fat digestion through named enzymes, products and gut locations, then connect pH conditions and solubility to nutrient absorption.
What is an example of chemical digestion?
breaking down starch into reducing sugars
churning of food by muscular contractions of the stomach wall
grinding of food by teeth
mixing of food with bile
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
Fig. 2.1 is a diagram of the human alimentary canal and associated organs.
Fig. 2.1
Table 2.1 shows enzymes, the organs that secrete these enzymes, their substrates and products.
Complete Table 2.1.
Table 2.1
Explain the role of hydrochloric acid in the alimentary canal.
Fig. 2.1 is a diagram of the human alimentary canal and associated organs.
Fig. 2.1
Explain the role of hydrochloric acid in the alimentary canal.
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.
Pepsin is a protease enzyme found in the alimentary canal.
State the organ in the alimentary canal where pepsin is secreted.
The same experiment was performed with trypsin, another protease enzyme.
Predict the optimum pH for trypsin.
Which substance causes the change in pH when food enters the small intestine?
amylase
bile
gastric juice
trypsin