Introduction to B.1 to B.6 and B.7 to B.10

Like all IB students you are likely to have a natural curiosity about who you are and how your body functions. You will very likely want to know the answers to questions like, ‘How is light converted into electrical signals in my eye?’, ‘Why do fatty foods increase the risk of heart disease?’ and ‘How can genetic information be stored in DNA?’ Option B contains the answers to all these questions and many more. It is one of the more popular options and students generally enjoy studying it as they can very easily relate to the material it covers.

Although some of the content of this option needs to be memorized a surprising amount can be deduced once the underlying theory is understood. The structures of any complex molecules that are required are given in Sections 31, 33, 34 and 35 in the IB Chemistry data booklet so the emphasis is more on recognising important functional groups contained within them and on their chemical properties and reactions rather than on recall. In terms of methodology there is some similarity with Option D: Medicinal chemistry as both involve reactions of chemical substances within the body. Much of the chemistry contained within this option can be a useful addition if you are also studying IB Biology as one of your six diploma subjects but there is actually very little overlap with the Biology syllabus. For this reason you should be warned not to answer questions on Option B when you take the Paper 3 examination unless you have actually studied this option. Knowledge of biology on its own will not be sufficient to gain many, if any, marks in Option B. It might be tempting to think that, like Option D, this option would also be a useful preparation tif you want to go on and study medicine. In reality it probably does not make much difference which one of the four options you study now that they all contain the same four strands of quantitative, analytical, environmental and organic chemistry. It might be worth mentioning though that the only analytical references in the core part of this topic are to paper chromatography and electrophoresis as ways of identifying amino acids. Using spectroscopy for analysis does not appear until the assay of proteins using UV-Vis spectroscopy in the Higher Level part of the option. Similarly the only clear reference to quantitative chemistry in the core part of the option is the determination of the iodine number for unsaturated fats.

The core part of this option basically gives an introduction to biochemistry (including metabolism, photosynthesis and respiration) then looks at the chemistry of proteins and enzymes, carbohydrates, lipids, vitamins and biochemistry and the environment (including green chemistry and xenobiotics). The additional Higher Level material covers the characteristics of enzymes (including enzyme kinetics, buffer calculations and the assay of proteins by UV-Vis spectroscopy) the chemical explanations behind the functioning of nucleic acids (including the genetic code and genetically modified foods), biological pigments and stereochemistry in biomolecules.