Midterm Review Flashcards
Which of the following factors or variables will NOT affect the Rf (retardation factor) values of solutes during the paper chromatography experiment?
A. solutes with different conformational isomers
B. paper type
C. solvent composition
D. all of the above
A. Solutes with different conformational isomers
Formula for percent error:
[Experimental - theoretical] / theoretical
\_\_\_\_\_ is used to quantify the accuracy of an experiment. A. percent error B. standard deviation C. regression coefficient D. best fit line
A. percent error
\_\_\_\_ is used to quantify precision of an experiment. A. percent error B. standard deviation C. regression coefficient D. best fit line
B. standard deviation
What portion of the amino acid structure determines the difference of polarity among different amino acids?
R-group
What is the most non-polar amino acid? A. Glycine B. Alanine C. Valine D. Leucine
A. Glycine
Under the same conditions as used in the paper chromatography lab which amino acid will have the most affinity for the stationary phase? A. Glycine B. Alanine C. Valine D. Leucine
C. Valine
\_\_\_\_\_\_ reagent was used to detect amino acids on the paper chromatogram. It reacts with \_\_\_\_ group of amino acids and gives purple colored product. A. Ninhydrin, hydrogen B. Bromophenol blue, R-group C. Ninhydrin, amino group D. Bromophenol blue, carboxyl
C. Ninhydrin, amino group
In gel filtration chromatography, the _____ (larger or smaller) proteins cannot enter the pores of the resin/matrix and thus elute _____ (earlier or later) from the column.
Larger; earlier
To elute target proteins from a gel filtration chromatography matrix, which of the following conditions would be the most appropriate?
A. change the pH of the elution buffer
B. gradually increase the salt concentration of the elution buffer
C. Adding soluble ligand to the elution buffer which competes with binding to the affinity tagged proteins to the column
D. Just keep adding the wash buffer through the column and start collecting samples
D. Just keep adding the wash buffer through the column and start collecting samples
To elute target proteins from an affinity chromatography column, which of the following conditions would be the most appropriate?
A. change the pH of the elution buffer
B. gradually increase the salt concentration of the elution buffer
C. Adding soluble ligand to the elution buffer which competes with binding to the affinity tagged proteins to the column
D. Just keep adding the wash buffer through the column and start collecting samples
C. Adding soluble ligand to the elution buffer which competes with binding to the affinity tagged proteins to the column
Which statement below about GFP and BFP is FALSE?
A. Researchers can now connect/tag GFP to other interesting, but otherwise invisible proteins. This glowing marker allows them to watch the movements, positions and interactions of the tagged protein
B. GFP occurs naturally in jelly fish, A. victoria, while BFP occurs naturally in blue fish.
C. Blue fluorescent protein is a derivative variant of the gfp. It has a His-66 substitution at the Tyr-66 position and a second substitution from Tyr-145 to Phe-145
D. A set of gfp and bfp proteins can be used as a dramatic tool to visually demonstrate the effect of pivotal amino acid changes on the structure and function of proteins
B. GFP occurs naturally in jelly fish, A. victoria, while BFP occurs naturally in blue fish.
Protein purification by affinity chromatography takes advantage of the ____ of the protein to be purified.
A. polarity
B. biological activity (affinity to ligand)
C. size
D. shape
B. biological activity (affinity to ligand)
In SDS-PAGE (gel electrophoresis), the denatured proteins are _____ (+ or - charged) because it binds to _____ (reagent) and moves towards the _____ electrode.
A. Neg, SDS, positive (anode)
B. Pos, glycerol, negative (cathode)
C. Neg, glycerol, positive (anode)
D. Pos, Coomassie Blue, negative (cathode)
A. Neg, SDS, positive (anode)
To determine the molecular mass of an unknown protein, you would use \_\_\_ form of the protein because it would overcome the \_\_\_ factor associated with its \_\_\_\_ form. A. denatured, shape, native B. denatured size, native C. native, shape, denatured D. native, size, denatured
A. denatured, shape, native
What reagent can you add (in SDS-PAGE) to the denatured protein sample to cause it to sink into the well instead of dispersing? A. glycerol B. SDS C. 2-mercaptoethanol D. Coomassie Blue E. NH4OH
A. glycerol
The reason for removing the tape that seals the bottom of a polyacrylamide gel cassette is to ____.
Allow electrical contact
When running SDS-PAGE, what is the purpose of heating the GFP and BFP before running them in the gel?
To denature and linearize the proteins
Place the following steps in correct order for affinity column chromatography.
I. wash the column
II. load protein extract
III. pack the column
IV. wash the column again
V. elute the column and collect fraction
A. III, I, II, IV, V
B. I, II, III, IV, V
C. III, II, I, V, IV
D. I, III, II, V, IV
A. III, I, II, IV, V
During the affinity chromatography experiment, when using 1M NaCl buffer to wash the column after loading the extract, ____ will elute from the column.
A. Any proteins present in the pores of the sephadex matrix or beads
B. Any proteins present in between the beads that has not entered the beads
C. Glucose binding proteins, which are bound to sephadex, strongly and specifically
D. A and B
E. all of the above
D. A and B
Phenylalanine would have the same retardation factor in solvent X (polar) as solvent Y (non-polar). T or F?
False
In SDS-PAGE (gel electrophoresis), the dye Bromophenol Blue is used to stain or visualize protein bands within the gel as it binds to proteins. T or F?
False
In denaturing gel electrophoresis (SDS-PAGE), the proteins are separated based on their shape. T or F?
False
The SDS-PAGE consists of two gels, first a stacking gel in which proteins are concentrated prior to entering the resolving gel, and the other, a resolving (or running) gel in which proteins are resolved on the basis of their molecular weights. T or F?
False
