(a)List four properties of proteins that are exploited in their purification. For each give an example of a protein purification procedure that takes advantage of that property.(2 marke) (b)Name two procedures that can be used to break open bacterial cells? In your answer, briefly state the principles behind how each method achieves this. 흐What conditions/reagents can be used to preserve the biological integrity of proteins once cells have been broken open? You must provide at least three examples and explain how the condition/reagent works to preserve the biological integrity of the proteins. (d)Use the table below to calculate the specific activity, fold purification and percent recovery for the last three stages of a purification procedure. Please show at least one full calculation for each column and where appropriate include the correct units.

(e)Explain what is meant by a crude extract (1 mark) and why ammoniumsulphate is often used as the first step in the purification procedure afterproducing a crude extract (2 marks). (f)Explain the effectiveness of using a CM-cellulose ion exchange chromatography for the purification of a protein with a pl of 6.7, when using a buffer with pH 7 42 6A small sample of the purified protein was run on an isoelectric focussing gel.Briefly, explain the technique and how an isoelectric focussing gel is set up.The answer should also include an explanation to the principle of isoelectric focussing.(2 marks)