Question 5
(a) (i) What is digestion? [2 marks]
(ii) Name two enzymes responsible for protein digestion. [2 marks]
(b) State six functions of the liver. [6 marks]
Observation
This question was attempted by many candidates and their performance was poor.
In part (a)(i) candidates could not correctly define digestion, they missed the definition and wrote definition for absorption and in (ii) candidates could not correctly name enzymes responsible for protein digestion and in part (b) candidates could not also correctly state functions of the liver.
However, the expected answers are as follows:
5(a)(i) DIGESTION
- Is a process involving the break down of large food molecules to small food molecules/insoluble to soluble nutrients.
- For the absorption of nutrients
(ii) ENZYMES RESPONSIBLE FOR PROTEIN DIGESTION
- trypsin
- pepsin
- renin
- erepsin
(b) FUNCTIONS OF LIVER
- regulates composition of blood/destroy old red blood cells
- production of bile
- deamination/production of nitrogenous waste
- storage of iron/copper/vitamins
- detoxication/detoxification
- production of heat/energy
- stores blood cells
- produces heparin
- converts some amino acid to carbohydrates
- converts glycogen into glucose vice versa/regulates blood sugar
- excretes bile pigment
- excretes cholesterol