Biochemistry
9th Edition
ISBN: 9781319114671
Author: Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.
Publisher: W. H. Freeman
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Chapter 29, Problem 10P
Interpretation Introduction
Interpretation:
The reason for the movement of helicases in a particular direction is to be determined.
Concept introduction:
During
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The enzyme lactate dehydrogenase (LDH) catalyzes the conversion of pyruvate to lactatein skeletal muscle cells using NAD/NADH during anaerobic “balanced” fermentation.Answer the following questions about this reaction.
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- The titration curve of alanine shows the ionization of two functional groups with pK values of 2.34 and 9.69, corresponding to the ionization of the carboxyl and the protonated amino groups, respectively. The titration of di-, tri-, and larger oligopeptides of alanine also shows the ionization of only two functional groups, although the experimental pK values are different. The table summarizes the trend in pK values. Amino acid or peptide Ala Ala-Ala pKj pk₂ 2.34 9.69 3.12 8.30 Ala-Ala-Ala 3.39 8.03 Ala-(Ala)-Ala, n ≥ 4 3.42 7.94 Modify the molecules to show the oligopeptide Ala-Ala-Ala. You can modify the molecules by moving, adding, deleting, or changing atoms, bonds, or charges. C Select c Draw Templates More H с N 0 S Cl H H | | || H CH3 H CH, H CH₂ Complete the statements about the the pK, values of the Ala-Ala-Ala oligopeptide. The pK₁ value of 3.39 is associated with the -COO group of Ala-Ala-Ala. The pK2 value of 8.03 is associated with the -NH group of Ala-Ala-Ala. Erase Q2 Q…arrow_forwardFacts from the bacterium mals and to dept kan apa in a peptide with antidic properties. This peptide complex with the call membrance of other hacterial species, leading in bacterial death The structure of the peptide has been determined from (a) Cmplete acid hydes of the peptide, followed by amino acid analys, yielded quiar anunt of Lan, Om, Pfx, Prxa, and Wall Cmtiti, an amino acid od prosentin pockets but present in some peptides. Com has the tracture H *H,N-CH-CH-CH, -C- COO (b) The weight of the peptide in approximately 1,200 Th (c) The peptide failed to undergo hydrolysis when treated with the Hydrolysis of the carbonyl-terminal residue of a polypeptide une "NH, the year. This call there Pro or the police does not contain a froz (d) Treatment of the peptide with 1-haw-2,4-dicherer (11N1), followed by complete hydrolysis and ched only from and the derivative NO, Н ON NHCHI CH, CH, C coo +NH, (Hint: The 2,4-diphenyl derivative involves the amino group of a side chain rather than the…arrow_forwardElectrophoresis Macmillan Learning Chymotrypsin is a protease with a molecular mass of 25.6 kDa. The figure shows a stained SDS polyacrylamide gel with a single band in lane I and three bands of lower molecular weight in lane 2. Lane I contains a preparation of chymotrypsin and lane 2 contains chymotrypsin pre-treated with performic acid. 1 2 Why does performic acid treatment of chymotrypsin generate three bands in lane 2? ° Chymotrypsin self-digests on the carboxyl-terminal side of phenylalanine, tryptophan, or tyrosine residues. The three peptides are impurities in the original chymotrypsin sample. Performic acid cleaves proteins on the carboxyl-terminal side of lysine and arginine residues. Performic acid cleaves the disulfide bonds holding together the three subunits of chymotrypsin. Correct Answerarrow_forward
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