Question

In: Chemistry

To the nearest hundredth of a unit, what is the net charge of the peptide AIGNECK...

To the nearest hundredth of a unit, what is the net charge of the peptide AIGNECK at pH 4.7? Use the following set of pKa values:

Group                pKa                                               

N-ter                 8.0

C-ter                 3.1

Asp or Glu         4.0

Lys                  10.5

Arg                  12.4

His                    6.0

Tyr                  10.5

Cys                   8.4

Also, use the approximation that if the separation between the pH and pKaof a group in question is 2 units or greater, then consider the group completely protonated or unprotonated as the case might be.

Answer should be 0.19, I just don't know how to get there.

Solutions

Expert Solution

* What you wish, is the EXACT charge on the peptide. For this you must use HH equation as instrusted below-

Ans. Calculation of Charge on peptide:

Note: Only the N-ter, C-ter, acidic (E) and basic residues (K) are used for calculating charge.

Method 1: Use Henderson-Hasselbalch equation for EXACT charge calculation

Net Charge (exact value) at pH 4.7 = + 0.190

#I. The residues with acidic side chain and C-terminal are written in RED/BOLD. Their corresponding charge is written in columns of “Acidic residues”. Ignore all other charge/values in “black ink”. The sum of charge in “RED ink” is the total –ve charge on the peptide at specified pH.

#II. The residues with basic side chain and N-terminal are written in Blue/BOLD. Their corresponding charge is written in columns of “Basic residues”. Ignore all other charge/values in “black ink”. The sum of charge in “Blue ink” is the total +ve charge on the peptide at specified pH.

#III. The charge on each residue/ group is calculated using Henderson-Hasselbalch equation as shown in respective column. That is, the charge on acidic residue is calculated using pH = pKa + log ([A-] [AH]).

The charge on basic residues in calculated using HH equation for base pOH = pKb + log ([BH+] / [B]); Where   B = Base , BH+ = Conjugate acid

#IV. Only residues with acidic and basic side chain are shown in excel for calculation.


Related Solutions

To the nearest hundredth of a unit, what is the net charge of the peptide AIGNECK...
To the nearest hundredth of a unit, what is the net charge of the peptide AIGNECK at pH 4.3? Use the following set of pKa values: Group                pKa                                                N-ter                 8.0 C-ter                 3.1 Asp or Glu         4.0 Lys                  10.5 Arg                  12.4 His                    6.0 Tyr                  10.5 Cys                   8.4 Also, use the approximation that if the separation between the pH and pKa of a group in question is 2 units or greater, then consider the group completely protonated or unprotonated as the case...
To the nearest hundredth of a unit, what is the net charge of the peptide AIGNECK...
To the nearest hundredth of a unit, what is the net charge of the peptide AIGNECK at pH 4.4? Use the following set of pKa values: Group pKa N-ter 8.0 C-ter 3.1 Asp or Glu 4.0 Lys 10.5 Arg 12.4 His 6.0 Tyr 10.5 Cys 8.4 Also, use the approximation that if the separation between the pH and pKa of a group in question is 2 units or greater, then consider the group completely protonated or unprotonated as the case...
Express monetary answers to the nearest whole dollar. Express percentage answers to the nearest hundredth 22.Tiffanywould...
Express monetary answers to the nearest whole dollar. Express percentage answers to the nearest hundredth 22.Tiffanywould like to buy a delivery vehicle for hersmall business. Shecan afford to make a down payment of $7,500 and pay monthly (end-of-month) payments of $1,350. If the term is 48months and the loan rate is 5.24 percent(APR), then what is the maximum that Tiffanycan pay for the delivery vehicle? 23Geraldpurchases a house for $250,000 by getting a mortgage for $225,000 and paying a down...
Figure the total balance owed for each of the following (round to the nearest hundredth): 1)...
Figure the total balance owed for each of the following (round to the nearest hundredth): 1) Retailer purchase items from whole seller with the following terms; shovels@ 12/ea; purchased 12 shovels on June 20 "10/10 net 30" brooms @8/ea ; purchased 50 brooms on June 30 "15/5 net 30" boxes of nails @ 50/each;purchased 20 boxes July 1 "2/10 net 30" **days of Holiday included towards total days counted Purchaser will pay bill "in full" today. How much does she...
Figure the total balance owed for each of the following (round to the nearest hundredth): 1)...
Figure the total balance owed for each of the following (round to the nearest hundredth): 1) Retailer purchase items from whole seller with the following terms; shovels@ 12/ea; purchased 12 shovels on June 20 "10/10 net 30" brooms @8/ea ; purchased 50 brooms on June 30 "15/5 net 30" boxes of nails @ 50/each;purchased 20 boxes July 1 "2/10 net 30" **days of Holiday included towards total days counted Purchaser will pay bill "in full" today. How much does she...
Find the net charge of the following peptide chain at ph 4 Please show all work...
Find the net charge of the following peptide chain at ph 4 Please show all work Lys-Ile-His-Glu-Tyr-Arg-Lys
Use the z-score table to answer the question. Note: Round z-scores to the nearest hundredth and...
Use the z-score table to answer the question. Note: Round z-scores to the nearest hundredth and then find the required A values using the table. A psychologist finds that the intelligence quotients of a group of patients are normally distributed, with a mean of 101 and a standard deviation of 16. Find the percent of the patients with the following IQs. (a) above 113 % (b) between 89 and 119 %
Complete this partial comparative balance sheet by vertical analysis. Round percents to the nearest hundredth. (using...
Complete this partial comparative balance sheet by vertical analysis. Round percents to the nearest hundredth. (using excel) Column1 Column2 Column3 Column4 Column5 2017 2016 Assets amount percent amount percent Current assets: a. Cash $38,000 $35,000 b. Accounts receivable $19,000 $18,000 c.merchandise inventory $16,000 $11,000 d. prepaid exoenses $20,000 $16,000 . . . . . . . . . total current assets $180,000 $140,000 What is the amount of change in merchandise inventory and the percent increase?
What will the total charge be for this peptide (T-H-R-I-P ) in a solution at pH...
What will the total charge be for this peptide (T-H-R-I-P ) in a solution at pH 5.52? Please make sure that your final answer and all associated calculations are clear (circle final answer if necessary)! (note that it is OK to consider any group fully (de)protonated when it is >2.0 pH units from its pKa). Don’t forget that you have scratch paper at the back of the test.
Directions: Show ALL work! Please round any answer to the nearest hundredth, unless you can get...
Directions: Show ALL work! Please round any answer to the nearest hundredth, unless you can get an exact amount. If an answer asks to explain, please make sure to give a valid and complete explanation. For your hypothesis tests, make sure you give a complete interpretation. 2. In a survey of 500 randomly selected U.S. teens, it was found that 37% of them have been in the car while a person under the influence is driving. a) Construct a 90%...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT