\fMass spectrometer You are using a mass spectrometer to analyze the composition of a protein. After digesting the protein down to amino acids (of mass m), the amino acids are vaporized and singly ionized (giving them a charge +q); the charged amino acids are accelerated by an electric field E over a distance d, after which they enter a region of uniform magnetic field. After a half-circle, they hit a position-sensitive detector a distance x from their entry point. acceleration region bending region E O V O B E O K d Cup-o-amino acids X O O O In Part A, you will work through the physics of a mass spectrometer. In part B, you will apply your result to deduce the composition of a protein from the mass spec output.Part A. 1. What is the speed v of the singly charged amino acids as they exit the acceleration region? Give your answer symbolically in terms of m, d, q and E. 2. What is the position x at which singly charged amino acids hit the detector, as a function of m, d, q, E and B? 3. How does x scale with the mass to charge ratio? That is, what is n in x o (m/q)"?Part B. 1. When you run a 1:1:1 calibration mixture of glycine, aspartic acid and tryptophan through the mass spectrometer you observe the following signal: 0.8 20.8 signal strength 0.4 0.2 40 50 70 80 x (mm) The peaks are at x = 40.33, 57.29 and 72.87 mm. Figure out which peak corresponds to which amino acid and label it appropriately on the graph.3 Use the amino acid masses on the last page: they are appropriate for digestive products as used in protein sequencing like we have here. If your formula from part A is correct, you should be able to check their exact locations (not just the order), which is basically equivalent to figuring out the constant of proportionality in the relation x = k(m/q)". This will be useful to you in the next question.2. You are analyzing a new protein and run it through the mass spectrometer, producing the red graph below. I've kept the blue reference curve on it as well. 0.8 signal strength 30.4 0.2 30 40 50 70 x (mm) The new peaks occur at x = 49.83, 54.23, 61.16 and 66.74 mm. Figure out which amino acids these peaks correspond to and label them on the graph.4 3. You know the mystery protein is exactly 21 amino acids long. What is its amino acid composition?5 One way to do this is to take your value of k (from the previous question) and invert x = k(m/q)" to solve for m - and then look up which amino acid has that mass in the table at the end of this document. There are more sophisticated variations of mass spectrometry where a protein is progressively digested from its end, and after each digestion the products are put through mass spec; or where the protein is only partially digested so that adjacent amino acids sometimes remain together. Either method provides additional information about not only which amino acids are in a protein, but where they occur.To help you out, here is a list of amino acid masses: Amino Mass Amino Mass Amino Mass acid (Da) acid (Da) acid (Da) Gly 57.0519 Ile 113.1594 Met 131.1926 Ala 71.0788 Leu 113.1594 His 137.1411 Ser 87.0782 Asn 114. 1038 Phe 147.1766 Pro 97.1167 Asp 115.0886 Arg 156.1875 Val 99.1326 GIn 128.1307 Tyr 163.176 The 101.1051 Lys 128.1741 Trp 186.2132 Cys 103.1388 Glu 129.1155 The imaginary protein in part B2 is absurdly small, but the principle behind the analysis is valid. The mass spec signal from a real protein is too complicated to analyze without computer help: 536.7 100 BO 70 424.9 60 636.6 804.4 LLLLLLLL 368.5 471.7 690.4 (64-77) Relative Abundance (%) 50 503.0 40 363.2 374.8 537.5 30 580.0 748. 631.4 691.2 20 342.9 752.5 815.9 909.1 943.5 708.8 992.4 1010.2 10 190.9 1184.8 1237.8 1270.3 1341.4 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 m/z Note that the x-axis on this graph is the mass/charge ratio, which is probably the easiest way to think about this process. The distance x that you calculated in part A is closely related to this (see part A3) but is not the same thing