Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Chemistry Expert

Compute the structural analysis of the protein.
1. The chirality of an amino acid results from the fact that its carbon:
i. has no net charge.
ii. is a carboxylic acid.
iii. is bonded to four different chemical groups.
iv. is in the l absolute configuration in naturally occurring proteins.
v. is symmetric.

2. Two amino acids of the standard 20 contain sulfur atoms. They are:
a. Cysteine and serine.
b. Cysteine and threonine.
c. Methionine and cysteine.
d. Methionine and serine.
e. Threonine and serine.

 

1293_amino acid.jpg


3. Which of the following statements about cystine is correct?
a. Cystine forms when the -CH2-SH R group is oxidized to form a -CH2-S-S-CH2- Disulfide Bridge between two cysteines.
b. Cystine is an ex of a nonstandard amino acid, derived by linking two standard amino acids.
c. Cystine is formed by the oxidation of the carboxylic acid group on cysteine.
d. Cystine is formed through a peptide linkage between two cysteines.
e. Two cystines are released when a -CH2-S-S-CH2- disulfide bridge is reduced to -CH2-SH.

4. Titration of valine by a strong acid, for ex HCl, reveals two pK's. The titration reaction occurring at pK2 (pK2 = 9.74)is:
a. -COO + H → -COOH
b. -COOH + -NH2 → -COO + -NH2+
c. -COO + -NH2+ → -COOH + -NH2
d. -NH2 + H → -NH3+
e. -NH + H → -NH2

5. For amino acids with neutral R groups, at any pH below the pI of the amino acid, the population of amino acids in solution will have:
a. a net negative charge.
b. a net positive charge.
c. no charged groups.
d. no net charge.
e. positive and negative charges in equal concentration.

6. At pH 8, the functional groups of histidine (pKa's are α-carboxylate=1.8, α-amino=9.3, imidazole=6.0)would be charged as follows:
a. -1 α-carboxylate, 0 α-amino, +1 imidazole = 0 net charge.
b. -1 α-carboxylate, +1 α-amino, +1 imidazole = +1 net charge.
c. -1 α-carboxylate, 0 α-amino, 0 imidazole = -1 net charge.
d. -1 α-carboxylate, +1 α-amino, 0 imidazole = 0 net charge.
e. α-carboxylate, +1 α-amino, +1 imidazole = +2 net charge.

7. What is the pI of aspartic acid? (use the pKa values of α-carboxylate=2.0, α-amino=10.0, β-carboxylate=4.0)
a. 7
b. 3
c. 1
d. 8
e. 4

8. In a protein experiment, the absorbance of a protein sample at 280 nm was 2.5. Using a molar extinction coefficient of 0.5/cmM, and a path length of 1 cm, find out the concentration of this protein in the sample.
a. 0.5 M
b. 3 M
c. 1.25 M
d. 5 M
e. 5 mM

9. Which of the following methods does NOT fractionate by size?
i. gel filtration chromatography
ii. isoelectric focusing
iii. SDS-PAGE
iv. gradient ultracentrifugation
v. all fractionate by size

10. Which of the following methods does NOT fractionate by charge?
a. action exchange chromatography
b. anion exchange chromatography
c. affinity chromatography
d. isoelectric focusing
e. only a & b

Chemistry, Academics

  • Category:- Chemistry
  • Reference No.:- M919279

Have any Question? 


Related Questions in Chemistry

The freezing point of a 1 molar nonelectrolyte such as

The freezing point of a 1 molar nonelectrolyte such as ethylene glycol is. What is the freezing point in degrees C of a 1.79 molar potassium chloride solution? Calculate the osmolarity of a solution made from a 1.876 % ( ...

Please create 1 synthesis you get to choose any starting

Please create 1 synthesis (you get to choose any starting material) but you should demonstrate all of the following reactions and the product: oxymercuration +hydroboration+ addition+ KMnO4 + hydrolysis + LDA . reactions ...

Using the debye-hucket equation calculate the activity

Using the Debye-Hucket equation, calculate the activity coefficients for the acidic and basic forms of bromocresol green, HX- and X2-, for a solution with an ionic strength of u=0.1M.

An empty 100-ml measuring cylinder weighs 132456 gnbsp when

An empty 100-mL measuring cylinder weighs 132.456 g.  When filled with rice to the 100-mL mark it weighs 220.345 g.  After water has been added to fill the spaces between the grains, the weight is 250.123 g.  What is the ...

What are the major sources and emissions of air pollution

What are the major sources and emissions of air pollution in your community? What chemicals are they emitting, and how are these chemicals transported through your community (non-point sources, smokestacks, etc.)? Were y ...

Write the balanced equation for the reaction of calcium

Write the balanced equation for the reaction of calcium metal with iron (III) nitrate. The coefficients on calcium metal and iron metal in the balanced equation are: 3 Ca(s) and 2 Fe(s) 2 Ca(s) and 3 Fe(s) 6 Ca(s) and 6 ...

What is the sum of all coefficients when the following net

What is the sum of all coefficients when the following net ionic equation is balanced using the smallest whole number coefficients possible? Do not forget coefficients of one. MnO 4 - + Mn 2+ MnO 2

1reacting molecules or ions in a solution at room

1. Reacting molecules or ions in a solution at room temperature are in constant motion and collide. Some collisions lead to formation of product and some don't. what determines a reaction will take place. 2. Is there any ...

A 100 l flask is filled with 100 g of argon at 25 c a

A 1.00 L flask is filled with 1.00 g of argon at 25 °C. A sample of ethane vapor is added to the same flask until the total pressure is 1.350 atm. What is the partial pressure of argon in the flask and what is the partia ...

You are provided with 200ml of 05moll-1 hydrochloric acid

You are provided with 200ml of 0.5molL-1 hydrochloric acid in which has been dissolved in a small quantity of anhydrous sodium carbonate. When titrated, 25ml of this solution requires 20.5ml of 0.5molL-1 sodium hydroxide ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro

Describe what you learned about the impact of economic

Describe what you learned about the impact of economic, social, and demographic trends affecting the US labor environmen