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Post-Lab Questions 1. Why must you use a pencil, and not ink or felt-tip pen, to mark on the paper the origin the amino acid preparations? Thhecnromaresra drs.peni Poupex is in While, en in en other hond wevid have Rum and smeared duia nexpen ment 2. In this experiment, suppose you forgot to mark the position of the solvent front when you tested the hydrolysate of aspartame against the other amino acids. Is it still possible to determine how many amino acids were present in the your answer a. hydrolysate? Explain es iti p08sble determine the amino acids b. Could you still identify what those amino acids were? Explain your answer. c. What can you not do? 3. There are polarity and molecular weight differences between aspartic acid and phenylalanine: Aspartic acid has a polar, acidic side chain and a smaller molecular weight: phenylalanine has a nonpolar side chain and a larger molecular weight. Based on the Re values you obtained for these two amino acids in the solvent employed, which amino acid migrated faster and two properties influenced the rate of migration? phanlanine mmegra Asparti c acid has three podr oos ane ou ami will m , tha any evidence that the aspartame in the kt Coca-Colas sample showed any hydrolysis into the two amino acids? no a. nto amino acids aspastic acid and 465 henylal omne
Expert Answer
1) We must use pencil beacause it is not soluble in solvents so it does not move on chromatographic paper ,But ink is soluble in solvents as a result it moves on chromatographic paper with your amino acids and creating junk on paper.This is why we always should use pencil not pen for spot .
2) a. Yes it is possible because RF value for each amino acid in perticular solvent is different so you will get different spot on chromatographic paper for each amino acid.solvent font line is necessary to calculate RF value.
b.Yes still you can identify those amino acids because more polar amino acid would move less and less polar amino acid would move more on chromatographic paper .
c. You can not calculate exact RF value if have not marked solvent font on your chromatographic paper.
3) Aspartic acid is more polar than phenylalanine so RF value for aspartic acid would be less which means phenylalanine migrated faster. nonpolar compound always moves faster than polar. molecular weight influence very less because of gravity more molecular weight compound moves little slow.But polarity always dominates on molecular weight .
4) aspartame has two amino acid as a result it hydrolysed in body as phenylalanine and aspartic acid
