Biuret Protein Assay

Question 1

Describe the scientific objective of the biuret protein assay experiment (what were we
trying to measure?)

Answer 1

protein per gram
of sample

Question 2

Explain why we used a standard curve

Answer 2

to
determine protein content in a sample of food

Question 3

what is a standard curve?

Answer 3

represent the relationship between two quantities.

Question 4

what is it used for ?

Answer 4

They are used to determine the value of an unknown quantity

Question 5

Know which protein was used as the standard to produce the standard curve

Answer 5

eggs

Question 6

Understand the function/use of spectrophotometer

Answer 6

instrument used to
measure the amount of light absorbed by a
solution.

Question 7

What did SDS do?

Answer 7

help to disrupt cellular membranes
and release proteins into solution

Question 8

centrifugation do?

Answer 8

the mixture is separated through spinning

Question 9

Glass beads?

Question 10

Vortex?

Answer 10

A mass of fluid, especially of a liquid, having a whirling or circular motion

Question 11

Explain how the Biuret reagent works and what it is used to measure

Answer 11

measure the concentration of protein
color turns violet

Question 12

Explain how the concentration of protein is related to the color of biuret reagent

Answer 12

reagent contains copper and sulfate
amide groups complex with copper at a basic ph result in a violet blue color

Question 13

Know how to read/interpret a standard curve graph (If given an absorbance of an
unknown sample, can you determine the protein concentration? Know how to estimate
and how to calculate the exact value