Human Diet & Digestion (CIE IGCSE Biology: Co-ordinated Sciences (Double Award))

The diagram below shows the organs of the digestive system.

 

In which organs does the digestion of proteins take place?

Which of the following is a correct cause and effect?

	deficiency	cause	effect
A	iron	diet deficient in red meat, leafy green vegetables and liver	brittle bones (rickets)
B	iron	lack of sunlight, fish and eggs	anaemia - tiredness and weakness due to not enough oxygen being delivered to tissues
C	vitamin D	lack of sunlight	brittle bones (rickets)
D	vitamin D	diet deficient in red meat, leafy green vegetables and liver	anaemia - tiredness and weakness due to not enough oxygen being delivered to tissues

Which of the following descriptions are correctly matched to the different stages of food breakdown?

	absorption	assimilation	egestion
A	small soluble food molecules move into the bloodstream	small soluble food molecules cross the cell membrane of cells	excretion of undigested or unabsorbed food through the anus
B	small soluble food molecules move into the bloodstream	small soluble food molecules cross the cell membrane of cells	passing out of undigested or unabsorbed food through the anus
C	small soluble food molecules cross the cell membrane of cells	small soluble food molecules move into the bloodstream	passing out of undigested or unabsorbed food through the anus
D	small soluble food molecules cross the cell membrane of cells	small soluble food molecules move into the bloodstream	excretion of undigested or unabsorbed food through the anus

Extended Tier Only

A student ate a meal which contained a type of biomolecule, X.

The digestion of biomolecule X started in the mouth, and finished in the duodenum.

What is the product of the digestion of biomolecule X?

Extended Tier Only

Below is a list of chemical reactions that occur during digestion.

1. Protein → amino acids
2. Starch → maltose
3. Lipids → fatty acids + glycerol
4. Maltose → glucose

Which of the chemical reactions above might occur in the duodenum?

Extended Tier Only

Which of the following shows the correct role of a substance made during digestion?

	substance	made by	effect
A	trypsin	stomach	digests proteins into amino acids
B	bile	gallbladder	neutralising acidic mixture of food entering the duodenum from the stomach
C	gastric juice	stomach	denaturing enzymes in harmful microorganisms and optimising pH for pepsin activity
D	bile	liver	neutralising alkaline mixture of food entering the duodenum from the stomach

The diagram below shows the organs of the digestive system, including the alimentary canal and accessory organs.

Where are most of the digestive lipase enzymes made in the body?