Turn over 17 9 The painkiller paracetamol can be synthesised from phenol in three steps. The percentage yield for each step is shown. OH OH NO2 OH NH2 OH NHCOCH3 Step 1 32% Step 3 70% Step 2 85% phenol paracetamol (a) In Step 1 another product also forms. The two products can be distinguished using their 13C NMR spectra. Complete the table to show the number of peaks in each 13C NMR spectrum. (2) Product OH NO2 NO2 OH Number of peaks in the 13C NMR spectrum (b) Calculate the minimum mass of phenol needed to synthesise 1.00 kg of paracetamol. [Mr values: paracetamol = 151.0 phenol = 94.0] (3) 18 (c) When metabolised in the body, paracetamol forms a toxic compound Z. This is then removed in the liver by a reaction with the tripeptide glutathione. OH NHCOCH3 O N O O NH2 HO O N H H N O O OH SH paracetamol compound Z glutathione (i) The conversion of paracetamol to compound Z is (1) A addition B hydrolysis C oxidation D reduction (ii) Draw a circle around each of the chiral carbon atoms in glutathione. (1) O NH2 HO O N H H N O O OH SH Turn over 19 (iii) Glutathione is formed from glycine and two other amino acids. Which two amino acids combine with glycine to form glutathione? (1) NH2 O OH NH2 HS O OH NH2 HO O OH O S O OH NH2 O OH NH2 HO O glycine cysteine aspartic acid methionine glutamic acid A aspartic acid and cysteine B glutamic acid and cysteine C glutamic acid and methionine D aspartic acid and methionine (d) Explain why amino acids such as glycine are crystalline solids at room temperature. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (Total for Question 9 = 10 marks)