Chemical Storylines- A2 Unit F334 Chemistry of Materials

CS What's in a Medicine?

More effective medicines can be obtained by modifying the structure of existing medicines
Combinatorial chemistry is used to make a large number of related compounds together, so that their potential effectiveness as medicines can be assessed by large-scale screening
Testing a medicine involved 3 stages of clinical trial
1. Is it safe?
2. Is it effective?
3. Is it better than the standard treatment?

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DNA is a condensation polymer formed from nucleotides, which are made up of a phosphate, a sugar and a base
Phosphate units join by condensation with deoxyribose in the sugar-phosphate backbone
The four bases of DNA (adenine, thymine, guanine and cytosine) join by condensation with the deoxyribose in the phosphate sugar backbone
Two strands of DNA form a double-helix structure through base pairing
DNA analysis can be used for genetic fingerprinting

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Stages of making steel
1. Removing sulphur- magnesium is added to reduce the sulphur to magnesium sulphide, which rises to the surface of the molten iron and is raked off
2.Removal of carbon, phosphorous and other elements- removed by direct oxidation with oxygen
3. Removal of oxides of phosphorous and silicon. The oxides are acidic, so must be removed. A mixture of calcium oxide and magnesium oxide is added to react with the acidic oxides.
Corrosion of steel is prevented by barrier protection with an oil, grease, paint of polymer, or sacrificial protection by galvanising and use of zinc blocks. The zinc corrodes in preference to the iron, so will protect the steel.

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