QUESTION 4 The table below shows the pka values for the various functional groups on cysteine. In which of the follow forms will cysteine predominantly be found at pH 9.1? group pka carboxyl (-COOH) 1.96 sulfhydryl (-SH) 8.18 ammonium (-NH3*) 10.13 А. В. CH,- SH CH,- SH H,N - CH-COOH H;N– CH- COo С. D. CH,-S CH,-S H,N CH-CO0 H,N- CH-COO- O A O B O c O D

QUESTION 4 The table below shows the pka values for the various functional groups on cysteine. In which of the follow forms will cysteine predominantly be found at pH 9.1? group pka carboxyl (-COOH) 1.96 sulfhydryl (-SH) 8.18 ammonium (-NH3*) 10.13 А. В. CH,- SH CH,- SH H,N - CH-COOH H;N– CH- COo С. D. CH,-S CH,-S H,N CH-CO0 H,N- CH-COO- O A O B O c O D

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

Experimental observations show that thiocyanate (SCN- ), the conjugate base of thiocyanic acid (pKa = 1.1 at 25 °C), is quite soluble in neutral water at pH > 2. In the space provided below, explain this experimental observation. That is, why does SCN– readily dissolve in water when the pH > 2?
4. Proteases are enzymes that catalyze the hydrolysis of peptide bonds in proteins. The enzyme trypsin is a protease that specifically hydrolyzes only those peptide bonds that are formed by the carboxyl group of basic amino acid residues. Trypsin is present in the small intestine where it functions at an optimum pH of 8. Consider the pentapeptide Phe-His-Val-Lys-Glu. Draw the structures of the products formed from trypsin-catalyzed hydrolysis of this peptide.
The isoelectric point (pl) can best be calculated by: Averaging the sums of all pkas. Averaging the sum of the two pKas closest to physiological pH. Averaging the two pKas "sandwiching" the zwitterionic form. Averaging the two pKas of the alpha-amino and alpha-carboxy groups.
Which of these structure represents cysteine at pH=13
Enz-SH + Ag* - Enz-S-Ag + H* The affinity of Ag* for sulfhydryl groups is so great that Ag* can be used to titrate -SH groups quantitatively. To 10.0 mL of a solution containing 3.5 mg/mL of a pure enzyme, an investigator added just enough AGNO, to completely inactivate the enzyme. A total of 0.536 umol AGNO, was required. Calculate the minimum molecular weight (M,) of the enzyme. minimum M, = The determined M, is not exact, but it is a minimum value for the M, of the enzyme. Why does the M, value obtained this way give only the minimum molecular weight? There is only one polypeptide chain. There are no disulfide bonds in the protein. There is only one titratable -SH group per protein molecule. The Ag* would also react with the terminal carboxyl group.
The R group of the amino acid Asp contains a carboxyl group with a pKa of 3.7. But the pka of the alpha-carboxyl group in Asp is 1.9. Which of the following. explanations could reasonably account for this difference? 3.7 is the isoelectric pH, which is estimated by averaging the pka of the alpha- carboxyl group with the much higher pKa of the alpha-amino group The R group of Asp also contains an NH2 group, which is less acidic than a carboxylic acid The conjugate base of the alpha-carboxyl could be stabilized by an attractive ionic interaction with the nearby alpha-amino group, which is protonated at low pH Water has better access to the R group than to the alpha-carboxyl group, so it more effectively solvates the charged form of the R group and stabilizes it
please help
Bha Please don't provide the handwriting solution
In addition to niacin, lovastatin is the other component of Advicor, Using the empiric method, determine the best classification for lovastatin (structure below) at pH =7. Note water solubility is defined as > 1% solubility HO CzeHasOs Answers A- B A Water-soluble B Fat-soluble
In the following reaction, the purpose of amino acid E193 is to: R, O. -O-P-O-Ad b204 NH, K13 Diminish the metal ion catalytic ability of Mg2*. Accept a proton transfer from S146. Stabilize the positive charge on K13. Anchor Mg2+ in the correct location.
Please don't provide handwriting solution
Which of the following amino acids is most likely to have a positively-charged side group under normal physiological pH conditions? O a. Lysine O b. Alanine O c. Leucine O d. Glycine O e. Aspartic acid Next page Previous page Time left 1:33:55 Quiz navigation 271 PM 今 D 572 2022 DELL Delete PgUp PgDn F12 PrtScr Insert F9 F10 F11 F7 F8 F5 F6 F2 F3 F4 Esc F1 Backspace & % %3D @ # 8 6 7 3 1 Y Enter J K A s D F ck St