Please help with 10 short practice questions. Biochem, related to protein.

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Please help with 10 short practice questions. Biochem, related to protein.

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Bio/Chem practice questions: 1. To remove a target protein into the liquid phase from the stationary phase during affinity chromatography, you must: a.) Increase the salt concentration. b.) Add the molecule to which your protein binds. c.) Increase the pH. d.) Apply an electrical current. e.) Use dialysis tubing. 2. How would you separate two proteins that have the same solubility in salt solution, same mass, and bind to the same target molecule? a.) SDS-PAGE b.) Dialysis c.) Trypsin digestion d.) Isoelectic focusing e.) Affinity chromatography 3. At pH 7, the peptide Met-Arg-Lys-Ser has a net charge of: a.) -2 b.) -1 c.) 0 d.) +1 e.) +2 4. During Edman degradation N-terminal amino acids first undergo a chemical reaction and then they are: a.) identified by trypsin digest b.) extracted into organic solvent c.) dansylated and identified by chromatography d.) cleaved off by an exopeptidase enzyme 5. If a gene duplication event within a specific species leads to a protein with a new function, the original protein and the new proteins are considered to be: a.) Paralogous proteins b.) Pseudogenes c.) Orthologous proteins d.) Homologous proteins 6. Any given domain of a protein cannot contain a.) Secondary structure

b.) Quaternary structure c.) Multiple helices d.) A mixture of alpha helices and beta sheets. 7. The DNA within a gene encoding an enzyme mutates so the protein now has an Alanine instead of an Aspartate. The enzyme’s function appears to be unaffected. The position of this residue can be considered to be: a.) A non-essential amino acid. b.) An invariant residue. c.) A hypervariable residue. d.) A conservatively substituted residue. 8. My dog’s fur is made largely of keratin. The keratin is ______________ than keratin in human’s skin because of _________________. a.) Weaker; hydrophobic effects b.) Softer; disulphide bridges c.) Harder; disulphide bridges d.) Stronger; ionic interactions 9. Draw the structure of the tripeptide at G-Y-D at pH 7. Label the Phi and Psi bonds for the middle residue (just with the symbols, not specific bond angles.) What is the net charge of this tripeptide at pH 7? 10. Describe what happens, biochemically speaking, to a sailor who got sick with scurvy during a voyage, and is recovering by eating fruits and vegetables.