CLS Review: Proteins, Electrophoresis, And Lipids –
Questions With Solutions
Kjeldahl's procedure for total protein is based upon the premise that:
a. proteins are negatively charged
b. the pKa of proteins is the same
c. the N content of proteins is constant
d. proteins have similar Tyr and Trp content Right Ans - c (16% by weight)
The term "biuret reaction" refers to:
a. the reaction of phenolic groups w/ CuSO4
b. coordinate bonds between Cu2+ and carboxyl and amino groups of biuret
c. the protein error of indicator effect producing color when dyes bind protein
d. the reaction of phosphomolybdic acid w/ protein Right Ans - b (Biuret =
CuSO4)
Which statement about the biuret reaction for total protein is true?
a. it is sensitive to protein levels below 0.1 mg/dL
b. it is suitable for urine, exudates, and transudates
c. polypeptides and compounds w/ repeating imine groups react
d. hemolysis will not interfere Right Ans - c (not sens. to protein < 0.1 g/dL
=> not for CSF, urine, transudates)
Which of the following protein methods has the highest analytical sensitivity?
a. Refractometry
b. Folin-Lowry
c. Turbidimetry
d. direct UV absorption Right Ans - b
Which of the following statements regarding proteins is true?
a. total protein and albumin are about 10% higher in ambulatory patients
b. plasma total protein is about 15% higher than serum levels
c. albumin normally accounts for about 40% of CSF total protein
d. transudative serous fluid protein is about two thirds of the serum level
Right Ans - a
hyperalbuminemia is caused by:
, a. dehydration syndromes
b. liver disease
c. burns
d. gastroenteropathy Right Ans - a
High serum total protein but low albumin is usually seen in:
a. multiple myeloma
b. hepatic cirrhosis
c. glomerulonephritis
d. nephrotic syndrome Right Ans - a (MM => decreased albumin synthesis)
Which of the following conditions is most commonly associated w/ an
elevated total protein?
a. glomerular disease
b. starvation
c. liver failure
d. malignancy Right Ans - d
Which of the following dyes is the most specific for measurement of albumin?
a. bromcresol green
b. bromcresol purple
c. tetrabromosulfophthalein
d. tetrabromphenol blue Right Ans - b
Which of the following factors is most likely to cause a falsely low result when
using the bromcresol green dye-binding assay for albumin?
a. penicillin
b. incubation time > 120 seconds
c. bilirubin
d. lipemia Right Ans - a
At pH 8.6, proteins are ____ charged and migrate toward the ____.
a. negatively; anode
b. positively; cathode
c. positively; anode
d. negatively; cathode Right Ans - a (anode = pos electrode)
Electrophoretic movement of proteins toward the anode will be made to
decrease by increasing the:
Questions With Solutions
Kjeldahl's procedure for total protein is based upon the premise that:
a. proteins are negatively charged
b. the pKa of proteins is the same
c. the N content of proteins is constant
d. proteins have similar Tyr and Trp content Right Ans - c (16% by weight)
The term "biuret reaction" refers to:
a. the reaction of phenolic groups w/ CuSO4
b. coordinate bonds between Cu2+ and carboxyl and amino groups of biuret
c. the protein error of indicator effect producing color when dyes bind protein
d. the reaction of phosphomolybdic acid w/ protein Right Ans - b (Biuret =
CuSO4)
Which statement about the biuret reaction for total protein is true?
a. it is sensitive to protein levels below 0.1 mg/dL
b. it is suitable for urine, exudates, and transudates
c. polypeptides and compounds w/ repeating imine groups react
d. hemolysis will not interfere Right Ans - c (not sens. to protein < 0.1 g/dL
=> not for CSF, urine, transudates)
Which of the following protein methods has the highest analytical sensitivity?
a. Refractometry
b. Folin-Lowry
c. Turbidimetry
d. direct UV absorption Right Ans - b
Which of the following statements regarding proteins is true?
a. total protein and albumin are about 10% higher in ambulatory patients
b. plasma total protein is about 15% higher than serum levels
c. albumin normally accounts for about 40% of CSF total protein
d. transudative serous fluid protein is about two thirds of the serum level
Right Ans - a
hyperalbuminemia is caused by:
, a. dehydration syndromes
b. liver disease
c. burns
d. gastroenteropathy Right Ans - a
High serum total protein but low albumin is usually seen in:
a. multiple myeloma
b. hepatic cirrhosis
c. glomerulonephritis
d. nephrotic syndrome Right Ans - a (MM => decreased albumin synthesis)
Which of the following conditions is most commonly associated w/ an
elevated total protein?
a. glomerular disease
b. starvation
c. liver failure
d. malignancy Right Ans - d
Which of the following dyes is the most specific for measurement of albumin?
a. bromcresol green
b. bromcresol purple
c. tetrabromosulfophthalein
d. tetrabromphenol blue Right Ans - b
Which of the following factors is most likely to cause a falsely low result when
using the bromcresol green dye-binding assay for albumin?
a. penicillin
b. incubation time > 120 seconds
c. bilirubin
d. lipemia Right Ans - a
At pH 8.6, proteins are ____ charged and migrate toward the ____.
a. negatively; anode
b. positively; cathode
c. positively; anode
d. negatively; cathode Right Ans - a (anode = pos electrode)
Electrophoretic movement of proteins toward the anode will be made to
decrease by increasing the:
