A cysteine found in the interior of a protein can act as a base in a...
A cysteine found in the interior of a protein can act as a base in a chemical reaction. Since the pH for living organisms is held constant near 7.3, what would have to happen to the pKa of the side chain (as a result of microenvironmental effects) to optimize cysteine’s ability to act as a base. Explain your answer.
Homework Answers
Cysteine contains a side chain with an -SH group. This acts as a nucleophile due to the lone pair electrons on the sulfur group, which is why it acts as a base. In order to optimize cysteine's ability to act as a base, its side chain should be deprotonated and the sulfur group should exist as -S-, and this happens when the pKa is lower than the pH.
However, this is not what happens at physiological pH. The pKa of cysteine side chain is 8.33 and at physiological pH, only a fraction of cysteine residues are deprotonated.
Add Answer to:
A cysteine found in the interior of a protein can act as a base
in a...
Acids are proton (H+) donors. Bases are proton (H+) acceptors. Acid-base reactions are often "rev...
Acids are proton (H+) donors. Bases are proton (H+) acceptors. Acid-base reactions are often "reversible", meaning that they can occur in both a left-to-right and a right-to-left direction. As a result, there is one acid and one base on each side of an acid-base reaction. 1. Identify the Acids and Bases on both sides of the following reactions: a. NH4+ + OH- ⟷ NH3 + H2O b. HCl + H2O ⟷ Cl- + H3O+ c. H2PO4- + H2O ⟷ HPO42- ...
It's a weak acid strong base titration Experiment 4: Identification of an unknown acid by titration...
It's a weak acid strong base titration
Experiment 4: Identification of an unknown acid by titration Page 2 of 15 Background In this experiment, you will use both qualitative and quantitative properties to determine an unknown acid's identity and concentration. To do this analysis, you will perform a titration of your unknown acid sample-specifically a potentiometric titration where you use a pH meter and record pH values during the titration, combined with a visual titration using a color indi- cator...
Acid precipitation can harm living organisms in rivers and streams, but some rivers are more vulnerable...
Acid precipitation can harm living organisms in rivers and streams, but some rivers are more vulnerable than others. Streams in the Adirondack Mountains, for example, were quickly acidified by acid precipitation in the 1970s and 80s, kiling local trout populations. But rivers that ran through a bed of limestone (calcium carbonate), like the Clark Fork River in Montana, were less affected. Part 8 of 10 What can explain the relative lack of effect of acid precipitation on the Clark Fork...
Please fill in the blanks! Shown below is a proposed mechanism for the cleavage of sialic...
Please fill in the blanks!
Shown below is a proposed mechanism for the cleavage of sialic acid by the viral enzyme neuraminidase. The kcat for the wild-type enzyme at pH 6.15,37 °C is 26.8s- Y409) Y409) (D149) (D149) онон ﹀R374-1st Step -ROH R' C-N R374 (E117) (E117) +H2O ↓ 2nd Step Y409) Y409) (D149) 8 ,0149 D149) OH OH H2N R374 (E117) (E117) Part A Describe the roles of the following amino acids in the catalytic mechanism: Glul17, Tyr409, and...
please help me type my introduction for my lab report. thank you!! INTRODUCTION In this section,...
please help me type my
introduction for my lab report. thank you!!
INTRODUCTION In this section, you will introduce the experiment by explaining generally what you did and why you did it. This section usually starts with an examination of the literature through a library search to inform the reader about work already done on this topic. If you have never done a bibliographic database search for scientific journal articles, then you are not yet a biological sciences major (note:...
Exercise 2 Separation of a Mixture Based on Acid-Base Properties One purpose of this exercise is...
Exercise 2 Separation of a Mixture Based on Acid-Base Properties One purpose of this exercise is to learn how to use a separatory funnel to extract a single component away from other compounds in solution. To do so, we will apply the principles of solubility and acid-base behavior you’re seeing in class. One of the compounds is neutral in the acid-base sense. It has no ability to either donate or accept a proton from an aqueous solution, and will remain...
A Case of Respiratory Distress Pre-Case Questions 1. In your own words, describe Le Chatelier's principle....
A Case of Respiratory Distress Pre-Case Questions 1. In your own words, describe Le Chatelier's principle. 2. What is PH? How do pH values change with increasing or decreasing H' content? Case A 68 year old woman, with no history of smoking presents to the ER for evaluation of dyspnea of greater than 1 hour in duration. Dyspnea or "air hunger" is considered normal when associated with heavy exertion; however this patient assured hospital staff she hasn't done anything which...
1. A calorie is a measure of the energy content of food. a. True b. False...
1. A calorie is a measure of the energy content of food. a. True b. False 2. Which chemical in the alcohol metabolic pathway is most toxic? a. ethanol b. acetaldehyde c. acetic acid d. none are toxic e. all are equally toxic 3. Which of the following are risks of long term regular use of alcohol. a. Increased cancer rates. b. Infertility and impotence. c. Diabetes. d. Liver disease. e. All of the above. 4. An amino acid is...
e. 18 Test Your Knowledge MULTIPLE CHOICE: Choose the one best answer. 1. Each element has...
e. 18 Test Your Knowledge MULTIPLE CHOICE: Choose the one best answer. 1. Each element has its own characteristic atom in which a. the atomic mass is constant. b. the atomic number is constant. c. the mass number is constant. d. Two of the above are correct. e. All of the above are correct. 2. Which of the following is not a trace element in the human body? a. iodine b. zinc c. iron d. calcium e. fluorine 3. A...
strand(s) and the RNA molecule is made up of strand(s). The DNA molecule is made up...
strand(s) and the RNA molecule is made up of strand(s). The DNA molecule is made up of O a. 4; 2 Ob. 1; 1 O c. 2; 1 O d. 1; 2 O e. 2; 4 QUESTION 45 The formation of large molecules from small subunits is known as what kind of reaction? O a reduction O b.condensation Oc decarboxylation d. hydrolysis O e. oxidation What is formed when an atom loses or gains an electron? O a. ion b....
It's a weak acid strong base titration
Experiment 4: Identification of an unknown acid by titration Page 2 of 15 Background In this experiment, you will use both qualitative and quantitative properties to determine an unknown acid's identity and concentration. To do this analysis, you will perform a titration of your unknown acid sample-specifically a potentiometric titration where you use a pH meter and record pH values during the titration, combined with a visual titration using a color indi- cator...
Acid precipitation can harm living organisms in rivers and streams, but some rivers are more vulnerable than others. Streams in the Adirondack Mountains, for example, were quickly acidified by acid precipitation in the 1970s and 80s, kiling local trout populations. But rivers that ran through a bed of limestone (calcium carbonate), like the Clark Fork River in Montana, were less affected. Part 8 of 10 What can explain the relative lack of effect of acid precipitation on the Clark Fork...
Please fill in the blanks!
Shown below is a proposed mechanism for the cleavage of sialic acid by the viral enzyme neuraminidase. The kcat for the wild-type enzyme at pH 6.15,37 °C is 26.8s- Y409) Y409) (D149) (D149) онон ﹀R374-1st Step -ROH R' C-N R374 (E117) (E117) +H2O ↓ 2nd Step Y409) Y409) (D149) 8 ,0149 D149) OH OH H2N R374 (E117) (E117) Part A Describe the roles of the following amino acids in the catalytic mechanism: Glul17, Tyr409, and...
please help me type my
introduction for my lab report. thank you!!
INTRODUCTION In this section, you will introduce the experiment by explaining generally what you did and why you did it. This section usually starts with an examination of the literature through a library search to inform the reader about work already done on this topic. If you have never done a bibliographic database search for scientific journal articles, then you are not yet a biological sciences major (note:...
A Case of Respiratory Distress Pre-Case Questions 1. In your own words, describe Le Chatelier's principle. 2. What is PH? How do pH values change with increasing or decreasing H' content? Case A 68 year old woman, with no history of smoking presents to the ER for evaluation of dyspnea of greater than 1 hour in duration. Dyspnea or "air hunger" is considered normal when associated with heavy exertion; however this patient assured hospital staff she hasn't done anything which...
e. 18 Test Your Knowledge MULTIPLE CHOICE: Choose the one best answer. 1. Each element has its own characteristic atom in which a. the atomic mass is constant. b. the atomic number is constant. c. the mass number is constant. d. Two of the above are correct. e. All of the above are correct. 2. Which of the following is not a trace element in the human body? a. iodine b. zinc c. iron d. calcium e. fluorine 3. A...
strand(s) and the RNA molecule is made up of strand(s). The DNA molecule is made up of O a. 4; 2 Ob. 1; 1 O c. 2; 1 O d. 1; 2 O e. 2; 4 QUESTION 45 The formation of large molecules from small subunits is known as what kind of reaction? O a reduction O b.condensation Oc decarboxylation d. hydrolysis O e. oxidation What is formed when an atom loses or gains an electron? O a. ion b....
Most questions answered within 3 hours.
-
What is the net ionic equation for the reaction that would occur
when an aqueous solution...
asked 48 minutes ago -
A
student bought $1000 worth of furniture. What is the equivalent
annual cost if it is...
asked 56 minutes ago -
What taboo subject did Ida B. Wells suggest was consensual
between black men and white women?...
asked 2 hours ago -
You have just been hired by the EPA to help with the new gas
mileage standards...
asked 3 hours ago -
4) A firm is hit by increases in its wage rate, w.
a) How does this...
asked 3 hours ago -
A square current loop 5.4 cm on each side carries a 510 mA
current. The loop...
asked 5 hours ago -
What are five tips in conducting knowledge assessment/literature
review research? Each of these tips needs to...
asked 6 hours ago -
Antigen presenting cells link innate and adaptive immune
responses. In the theoretical scenario where phagosomes cannot...
asked 6 hours ago -
Dealing with conflict, in my opinion, is a skill and an art. I
believe that those...
asked 7 hours ago -
6. A long straight wire with circular cross section and radius
1.5 cm carries a 1.2...
asked 7 hours ago -
Deacon Corporation has provided the following financial data
from its balance sheet and income statement:
Year...
asked 7 hours ago -
List and discuss at least three variables from everyday life for
which you expect the variable ...
asked 7 hours ago