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    Chromatography

    Advantage of Sequencing a Protein in Separate Samples

    The advantage of treating separate samples of a protein with two or more enzymes when sequencing a protein is that the products are a. more homogeneous b. sequenceable with out further chromatography c. fragments with the same N- and C-terminal amino acids d. fragments with sequence overlaps e. all are true

    PI (isoelectric poin)

    Based on predicted pI (for example, a pI for turnip peroxidase is 9.10), how can you use DEAE-sepharose to further purify peroxidase?

    Separating and Identifying Isomers

    (See attached file for full problem description with diagram) Question 1: List three methods in laboratory (I guess this means not involving high-tech instrumentation like in gas-liquid chromatography) to separate and identify the four reaction products in the above reaction. What are the advantages and disadvantages for each

    Biochemistry Questions: Ionization and Substrate Binding

    1. If the active site of a dipeptidase contains a glutamic acid residue (pKa 3.3) and a histidine residue (pKa 6.7), both of which must be charged for the substrate to bind, what is the optimal pH for substrate binding? 2. Lysozyme catalyzes the hydrolysis of C-O-C bonds between sugar residues in bacterial cell walls. The p

    Determining amino acid sequences of peptide and octapeptide

    1. What is the amino acid sequence of the peptide? The complete hydrolysis of an unknown nonapeptide revealed the presence of Glu, Val, Val,Gly,Lys, Lys, Tyr, Thr and Phe residues. The first amino acid to be detected as a phenylthiohydantoin derivative on Edman degradation of the peptide was glutamic acid. The only amino ac

    Determine the primary structure of the peptide

    In trying to deduce a primary structure of an peptide sequence... When does a polypeptide NOT contain a free carboxyl group? Are all peptides linear (or can they have a cyclic C-terminus)? What happens when treatment of the intact peptide with 2,4-dinitroflourobenzene (followed by complete hydrolysis and chromatography) y

    Chromatography Elution

    Question: Sketch the expected chromatographic elution profile (protein concentration vs elution volume) if a mixture of these proteins is applied to a weak anion exchange resin such as DEAE cellulose at a pH of 7. Label and show the salt gradient used for elution. Protein: (A), pI 8, MW 25000 (B) , pI 10, MW 10000 (C) , pI

    Ethyl Acetate as an Elution Solvent

    Caffeine is soluble in ethyl acetate. Do you think that the purity of your product could be checked by TLC using ethyl acetate as an elution solvent? Explain.

    TLC and Ethyl Acetate

    a) Caffeine is soluble in ethyl acetate. Do you think that the purity of the product could be checked by TLC using ethyl acetate as an elution solvent? b) We draw color spots on TLC plates for easier visualization after elution with solvent, the plates can be "developed" in a sealed chamber containing solid iodine. Explain