Keeping Healthy

A Year Ten module from the Salters’ double award science course. Practical tests using “urine” samples illustrate chemical diagnostic testing for illness. Different types of illness are classified, also different types of micro-organisms and the body’s defences against them. Experiments show how bacteria grow and measure the effectiveness of germicides. The concentration of different bleaches is measured.

A role-play casts students as ‘medical experts’ in deciding how to treat infection from a cut. The composition of blood, and its action in sealing wounds by clotting are discussed. Text exercises illustrate the immune system, antibodies and immunisation. The history of the eradication of smallpox is described. Dialysis tubing is used to model the role of the kidneys in removing impurities from blood. The working of artificial kidney machines is described. The properties of enzymes are introduced through experiments. A ‘cut-and-fit’ paper model of the lock-and-key theory of enzyme action shows how enzyme blockers work.

Section 1: What is meant by ‘being healthy’? Text exercises introduce ideas about personal and public health care, and the difference between being healthy and being fit.

Section 2: What is meant by ‘being ill’? Practical tests using “urine” samples illustrate chemical diagnostic testing. Different types of illness are classified. Different types of micro-organisms and the body’s defences against them are studied. The story of the discovery of the cause of malaria illustrates how medical science can help to improve prevention, diagnosis and treatment of illness.

Section 3: How do bacteria grow? Practical work with cultures shows how bacteria grow. Further experiments measure the effectiveness of different germicides, and experiments compare the concentration of bleaches.

Section 4: How does the body respond to invasion? A role-play casts students as ‘medical experts’ in deciding how to treat infection from a cut. The composition of blood, and its action in sealing wounds by clotting are discussed, followed by a series of worksheets on the immune system, antibodies and immunisation. There is also a history of the long battle to eradicate smallpox.

Section 5: Keeping the blood clean Models illustrate the role of the kidneys in removing impurities from blood. The working of artificial kidney machines is described.

Section 6: Chemical reactions in the body An investigation of peroxidise activity introduces ideas about the properties of enzymes. A ‘cut-and-fit’ paper-based exercise explains the lock-and-key theory of enzyme action and shows how enzyme blockers work.