Spectrophotometric Determination of Protein Concentrations Flashcards
______ describes the technology that focuses on the interaction of biological materials with _____ and other forms of radiant energy whose quantum unit is the _____.
Biophotonics; light; photon
_____ is energy that comes from a source and can travel through material or space.
Radiation
Mnemonic to remember the electromagnetic spectrum?
What does it mean?
Raging Martians Invade Venus Using X-Ray Guns
A few ways to remember the order of the Electromagnetic radiation spectrum’s wavelength from low to high frequency, from lowest to highest in energy:
Radio waves, Microwaves, Infrared, visible light (Red, Orange, Yellow, Green, Blue, Indigo, Violet), Ultraviolet, X-rays, and Gamma rays.
Tissues and cells are composed of what 4 different biomolecules?
DNA, proteins, lipids, carbohydrates
In what 4 ways can light interact with biomolecules?
reflection, absorption, transmission, light scattering
The ________ is based on the absorption of light as a function of wavelength.
Bradford assay
As light passes through a material, _________ is absorbed, and each material absorbs _____ at a specific ______.
light energy; light; wavelength
The removal of these wavelengths from visible light gives the material its ______.
color
The removal of yellow wavelengths of light by the protein-dye complex at 595 nm makes the protein-dye complex _______, while the dye alone (without protein) absorbs light at 470 nm making the dye a ________ color.
blue; reddish-brownish
Nearly all biophotonic applications involve a light source that is passed through a target material and a ___________ that reads the ________ from the material.
detection sensor; light emission
A __________ has a light source that generates specific wavelengths.
spectrophotometer
The light path ___ through the cuvette, is ______ by the material in the cuvette, and is read by a ________.
passes; absorbed; detector
In the Bradford assay, the peak absorbance of ______ Coomassie G-250 dye is at ____ nm, and the _______ is set to read 595 nm.
unprotonated; 595 nm; spectrophotometer
___________ use standard curves created by measuring the ____________ of solutions of known concentration to determine the concentration of unknown samples.
Colorimetric assays; absorbances
What are 3 colorimetric methods for determining the total protein content of a sample?
biuret; Lowry and Bradford
Which is the oldest method and is commonly used in high school labs to detect the presence of a protein?
biuret
How many reactions does the biuret involve?
2: chelation and redox
Of the 3 colorimetric methods, which is the least sensitive?
biuret
Which of the 3 colorimetric methods involve 2 redox reactions?
Lowry
What is a redox reaction?
a type of chemical reaction that involves a transfer of electrons between two species.
Think the mnemonic OIL RIG.
What is OIL RIG?
Oxidation is the LOSS of electrons.
Reduction is the GAIN of electrons.
The formation or presence of bonds (or other attractive interactions) between two or more separate binding sites within the same ligand and a single central atom.
chelation
The Lowry assay is affected by ______ from many common lab reagents and chemicals.
interference
Of the 3 colorimetric methods, which is the most sensitive?
Bradford protein assay