Proteins part 4 Flashcards
What is the product color of Biuret method?
Purple color
- Copper binds to the peptide bond
Biuret method
- Protein + CuSO4 + NaOH + Rochelle salt = ____________
PURPLE CHROMOGEN
Biuret method is based on the formation of the violet-colored chelate between cupric ions and requires at least ______ peptide bonds. Measured at __________
2
540nm
In this method, molecules are formed when Urea is heated at 180◦C.
Biuret
- 2 molecules of urea form _____ molecule of biuret
one (2:1)
__________ is preferred for Biuret reaction
Kinetic Biuret method
These will not be detected using a Biuret method.
Amino acid and Dipeptide
What are the reagents used in Biuret method?
a. Alkaline Copper Sulfate
b. Sodium Hydroxide
c. Rochelle’s salt
d. Potassium iodide
c. Rochelle’s salt = ___________________
Sodium Potassium Tartrate
- Used to complex Cupric ion and prevent their precipitation
Rochelle’s salt
- Keeps Copper in the Cupric form
Potassium iodide
- These 3 causes false increase in the range of Biuret method
a. High bilirubin
b. Elevated lipids
c. Hemolyzed samples
- Causes false decrease levels
d. High Blood Ammonia levels
- Tyrosine & Tryptophan reduce PT-PMA reagent (folin-ciocalteu) to give a ______________
BLUE COLOR
These reduces PT-PMA reagent
Tyrosine and Tryptophan
- F-CTM or Lowry Method detects proteins in low concentration, how low?
10-60ug/mL