Proteins part 4

Question 1

What is the product color of Biuret method?

Answer 1

Purple color

Question 2

• Copper binds to the peptide bond

Answer 2

Biuret method

Question 3

• Protein + CuSO4 + NaOH + Rochelle salt = ____________

Answer 3

PURPLE CHROMOGEN

Question 4

Biuret method is based on the formation of the violet-colored chelate between cupric ions and requires at least ______ peptide bonds. Measured at __________

Answer 4

2
540nm

Question 5

In this method, molecules are formed when Urea is heated at 180◦C.

Answer 5

Biuret

Question 6

• 2 molecules of urea form _____ molecule of biuret

Answer 6

one (2:1)

Question 7

__________ is preferred for Biuret reaction

Answer 7

Kinetic Biuret method

Question 8

These will not be detected using a Biuret method.

Answer 8

Amino acid and Dipeptide

Question 9

What are the reagents used in Biuret method?

Answer 9

a. Alkaline Copper Sulfate
b. Sodium Hydroxide
c. Rochelle’s salt
d. Potassium iodide

Question 10

c. Rochelle’s salt = ___________________

Answer 10

Sodium Potassium Tartrate

Question 11

• Used to complex Cupric ion and prevent their precipitation

Answer 11

Rochelle’s salt

Question 12

• Keeps Copper in the Cupric form

Answer 12

Potassium iodide

Question 13

• These 3 causes false increase in the range of Biuret method

Answer 13

a. High bilirubin
b. Elevated lipids
c. Hemolyzed samples

Question 14

• Causes false decrease levels

Answer 14

d. High Blood Ammonia levels

Question 15

• Tyrosine & Tryptophan reduce PT-PMA reagent (folin-ciocalteu) to give a ______________

Answer 15

BLUE COLOR

Question 16

These reduces PT-PMA reagent

Answer 16

Tyrosine and Tryptophan

Question 17

• F-CTM or Lowry Method detects proteins in low concentration, how low?

Answer 17

10-60ug/mL

Question 18

• Detects proteins in low concentration (10-60 ug/mL)

Answer 18

FOLIN-CIOCAL TEU METHOD / LOWRY METHOD

Question 19

• Widely used in research to measure tissue and enzyme proteins

Answer 19

FOLIN-CIOCAL TEU METHOD / LOWRY METHOD

Question 20

• Not satisfactory for urine and CSF protein determination

Answer 20

FOLIN-CIOCAL TEU METHOD / LOWRY METHOD

Question 21

In Folin-ciocal Teu method, the specimens are mixed with an _______________ followed by the addition of the_____________

Answer 21

Alkaline Copper solution
Lowry method.

Question 22

composed of phosphotungstic acid + molybdic acid which are used to reduce tungsten blue by copper complex with peptide and by tyrosine and tryptophan

Answer 22

Phosphotungstomolybdic acid

Question 23

Phosphotungstomolybdic acid is composed of?

Answer 23

phosphotungstic acid + molybdic acid

Question 24

What do phosphotungstic acid + molybdic acid reduce?

Answer 24

tungsten blue by copper complex with peptide and by tyrosine and tryptophan

Question 25

In Lowry method, The absorbance product are measured at a wavelength of ________. Dependent on the phenolic groups.

Answer 25

650-700nm.

Question 26

Due to the high electron density of aromatic rings of tyrosine and tryptophan in solution (pH 8)

Answer 26

ABSORPTION OF UV LIGHT AT 280nm

Question 27

Employed to stain protein bonds after electrophoresis

Answer 27

Dye-binding methods

Question 28

Analysis of fluid with lower protein concentration such as urine and CSF

Answer 28

Pyrogallol red

Question 29

Is the most sensitive, specific and the most precise among the dye-binding assays

Answer 29

Bromcreasol purple

Question 30

Albumin at pH 4.2 is cationic and binds with anionic dye

Answer 30

BCG

Question 31

It is the most commonly used dye and has to measure the absorbance

Answer 31

BCG

Question 32

- Is used in urine reagent strips - Sensitive to Albumin

Answer 32

Tetrabromphenol blue

Question 33

Sensitive to AA

Answer 33

Ninhydrin

Question 34

HABA refers to?

Answer 34

(2,4-dihydroxyazobenzenebenzoic acid)

Question 35

Rapidly estimates protein at high concentrations. Often used in urine specimen.

Answer 35

REFRACTOMETRY

Question 36

Turbidimetry and Nephelometry is AKA as?

Answer 36

Salt precipitation

Question 37

What are the precipitating agents of Turbidimetry and Nephelometry?

Answer 37

SSA Trichloroacetic acid

Question 38

 Precipitates all forms of proteins

Answer 38

SSA

Question 39

 Precipitates Globulins than Albumins

Answer 39

Trichloroacetic acid

Question 40

This method are often used for measuring urine and CSF protein

Answer 40

Turbidimetric

Question 41

Can used _______ Chloride under the alkaline condition and ________________ under alkaline conditions

Answer 41

Benzethonium Benzalkonium salts

Question 42

Determines the movement of proteins during the alkaline electrophoresis from the origin towards the ANODE.

Answer 42

PROTEIN ELECTROPHORESIS

Question 43

protein donates protons = (-) charge. Therefore migrates towards Anode

Answer 43

Alkaline ph

Question 44

Protein receives protons = (+) charge * Migrates towards the cathode

Answer 44

Acidic pH