METHODS FOR TOTAL PROTEIN

Question 1

Classical method for protein quantitation

Answer 1

Kjeldahl Method

Question 2

Reference method but not routinely used; TIME
CONSUMING

Answer 2

Kjeldahl Method

Question 3

Kjeldahl Method

Measures the amount of __________ in specimen

Answer 3

Nitrogen

Question 4

Kjeldahl Method

1 g of nitrogen = ?

Answer 4

6.54 g of proteins

Question 5

Kjeldahl Method

3 STEPS:

Answer 5

a. DIGESTION
b. DISTILLATION
c. TITRATION

Question 6

COMPONENTS OF THE PROTEIN:

Answer 6

CHON –
carbohydrate, oxygen and nitrogen

Question 7

Measures protein based on the number of peptide
bonds present.

Answer 7

Biuret Method

Question 8

Biuret Method

More peptide = ?

Answer 8

darker the color

Question 9

The darker the color the more protein present in
the sample

Answer 9

Biuret Method

Question 10

Biuret Method

The ______ present will bind to the peptide bonds
present in the protein forming

Answer 10

Copper

Question 11

Biuret Method

peptide copper
complex = ?

Answer 11

violet

Question 12

Most widely used method for total protein
determination

Answer 12

Biuret Method

Question 13

Biuret Method

_______ because the end product has color
(“DEEP COLOR PURPLE”/VIOLET)

Answer 13

Colorimetric

Question 14

Biuret Method

principle pr reagent do
not utilize enzyme

Answer 14

Non-enzymatic method

Question 15

Biuret Method

Reagent consists:

Answer 15

a. Alkaline CuSO4
b. Sodium potassium tartrate (Rochelle
salt)
c. NaOH
d. Potassium iodide –

Question 16

Biuret Method

Absorbance of color is read at ?

Answer 16

540 nm

Question 17

Biuret Method

present in protein forms a
bond with cupric ions forming a violetcolored chelate.

Answer 17

Copper

Question 18

Biuret Method

INTERFERENCE:

Answer 18

lipemic sample

Question 19

Has the highest analytical sensitivity which
measures small concentration of protein

Answer 19

Folin-Ciocalteu (Lowry) Method

Question 20

Folin-Ciocalteu (Lowry) Method

Principle: ______ __ _________ ______ such as tyrosine, tryptophan, and histidine.

Answer 20

Oxidation of phenolic compounds

Question 21

Folin-Ciocalteu (Lowry) Method

tyrosine, tryptophan, and histidine to
give a ?

Answer 21

Deep blue color

Question 22

Folin-Ciocalteu (Lowry) Method

MOLYBDIC
ACID OR PHENOL REAGENT; oxidize phenolic
compounds

Answer 22

PHOSPHOTUNGSTIC

Question 23

Folin-Ciocalteu (Lowry) Method

the reagent will reduce which is
measured

Answer 23

spectrophotometrically

Question 24

Folin-Ciocalteu (Lowry) Method

Color enhancer:

Answer 24

BIRURET REAGENT

Question 25

The absorbance of proteins at 210nm is due to the absorbance of the peptide bonds at specific wavelength.

Answer 25

UV Absorption Method

Question 26

UV Absorption Method Majority of proteins has absorbance of 210 except if there is ________ which is absorption at 280nm.

Answer 26

aromatic amino acid

Question 27

UV Absorption Method tryptophan, tyrosine, and phenylalanine absorption at ?

Answer 27

280nm

Question 28

based on measurement of refractive index of serum total protein.

Answer 28

Refractometry

Question 29

Refractometry Based how protein bend light and the changes is ______ due to the concentration of protein in the sample.

Answer 29

proportional

Question 30

Refractometry More changes in light = ?

Answer 30

high protein in sample

Question 31

Measurement depends on formation of a uniform fine precipitate which scatters incident light in suspension (NEPHELOMETRY) or block light (TURBIDIMETRY).

Answer 31

Turbidimetry and Nephelometry

Question 32

used for detection of proteins as little as 1 ug

Answer 32

Coomasie Brilliant Blue Dye

Question 33

develops violet color by reacting with primary amines widely used for detection of peptides and amino acids after paper chromatography

Answer 33

Ninhydrin

Question 34

Separation technique

Answer 34

Serum Protein Electrophoresis (SPE)

Question 35

Migration of charged particles in an electric field

Answer 35

Serum Protein Electrophoresis (SPE)

Question 36

Serum Protein Electrophoresis (SPE) cathode

Answer 36

Negative terminus electrode

Question 37

Serum Protein Electrophoresis (SPE) anode

Answer 37

Positive terminus electrode

Question 38

Serum Protein Electrophoresis (SPE) Protein will migrate in the anode because its ?

Answer 38

amphoteric

Question 39

Serum Protein Electrophoresis (SPE) proteins charge is negative

Answer 39

Increase p H(basic)

Question 40

Serum Protein Electrophoresis (SPE) the protein charge is positive

Answer 40

Decrease p H(acidic)

Question 41

Isoelectric Property of Proteins either positive or negative depending on pH condition

Answer 41

AMPHOTERIC

Question 42

Isoelectric Property of Proteins ph where the charge of protein is 0

Answer 42

No charge at ISOELECTRIC POINT

Question 43

The acidic and basic amino acids content of proteins determines its net charge.

Answer 43

Isoelectric Property of Proteins

Question 44

Isoelectric Property of Proteins amine and carboxylic acid

Answer 44

Positive and negative component

Question 45

Isoelectric Property of Proteins pH 8.6 which is basic

Answer 45

BARBITAL (VERONAL)