The elements of life

1. The elements of life EL 2 Take two elements

2. A trace is all you need • Trace and ultra elements, although they make up only the remaining 1% are essential for life • The ultra trace elements, cobalt, copper, iodine, iron, manganese, molybdenum, silicon, vanadium and zinc are not given because their quantities are so small

3. Uses of some trace elements

4. Oxygen can be attached to central Fe An Iron story • Iron carries out a vital role in the body: as part of the substance haemoglobin, present in blood, it is responsible for the transport of oxygen

5. An Iron story • Body can easily become deficient in iron, particularly in young teenagers who are growing quickly. Anaemia can be cured easily with iron tablets and an alteration in diet • There can also be too much iron in the body due to a genetic disorder. • Over a lifetime the body can accumulate many times the normal quantity of iron which is stored in many organs including the liver. This can only be treated by taking blood from the patient

6. An Iron story • The haemoglobin molecule consists of an iron atom at the centre of a ring structure. • The ring is the haem part of the molecule. • Also associated with the central iron atom is the protein - globin

7. An Iron story • Haemoglobin is able to do its job because oxygen molecules become attached to the Fe atom. • Oxygen isn’t the only substance to behave in this way. Carbon monoxide also behaves like this but it is attracted more strongly attracted than oxygen therefore it is a poison (preventing oxygen bonding with the Fe atom and being carried in the blood) • Smokers are prone to heart disease because cigarette smoke contains CO so the heart has to work harder to supply the body with oxygen

8. An Iron story • Blood donors are tested to see if enough iron is present in their blood. • A drop of blood is taken and placed in a solution of copper sulphate. • Reacts with haemoglobin to form an insoluble compound which appears as a white blob. • If the blob sinks the donor has enough haemoglobin (therefore Fe) to be able to donate safely

9. A Calcium story • Ca is essential for the development of bones, especially in children and young people • Pregnant women should eat a calcium rich diet to ensure that her bones remain strong, but her baby’s bones are properly formed

10. A Calcium story • Demineralised bones are referred to those that have insufficient calcium • Osteoporosis is caused by a lack of calcium, people with the disease tend to suffer from fractures and curvature of the spine.

11. A Calcium story • Increased uptake of calcium can help osteoporosis • Scientists wanted to find out how much calcium was taken up by the blood and becomes part of the bones • To do this we can use a tracer technique • Patients given a meal containing a radioactive calcium isotope and the amount of the radioactive calcium taken up by the blood stream was then measured

12. A Calcium story • Radioactive isotopes can be dangerous • Alternative was to use strontium (v. similar to calcium) much safer • This idea came from when observations were made during the 1960’s that children had much higher levels of strontium in their bones than was expected. • It was thought to come from atmospheric strontium – 90 which came from nuclear weapons testing in the fifties • Strontium is taken up in the bones just like calcium

13. A Calcium story • Strontium can be analysed in the presence of calcium because it gives a characteristic red light when put in a flame. The intensity of the light is a measure of the amount of strontium • The ability to monitor the patterns of calcium absorption through the use of non-radioactive strontium has led to greater understanding of calcium deficiencies and improvements in the treatment of bone disorders like osteoporosis • Ca content of bones can now be routinely monitored in hospitals. The procedure is quick and accurate and involves measuring bone density by comparing the transmission of X- rays and soft tissue