Term
| What does ninhydrin react with? |
|
Definition
| primary and secondary amines |
|
|
Term
| If ninhydrin reacts with proline what colour will be observed? |
|
Definition
|
|
Term
| If ninhydrin reacts with amines, what colour will be observed? |
|
Definition
|
|
Term
Cation exchange columns contain _____ groups with bind ______ molecules
(negative/position) |
|
Definition
negative
bind positive molecules |
|
|
Term
| How might you elute peptides from an ion exchange column? |
|
Definition
-competition (increase the concentration of ions so the amino acid gets displaced)
-change the pH (the charge on the AA will change so it no longer binds to the resin) |
|
|
Term
| What determines how tightly an amino acid binds to the resin in an ion exchange column? |
|
Definition
| the magnitude of the charge |
|
|
Term
| What are the two processes involved in amino acid analysis? |
|
Definition
1. Separation
2. Identification |
|
|
Term
True or False
Identification of amino acids can be qualitative, quantitative, preperative |
|
Definition
|
|
Term
| On what basis does partition chromatography separate amino acids? |
|
Definition
|
|
Term
| In partition chromatography, if the solvent is non polar and the particles are polar, which type of amino acid will elute first? |
|
Definition
| the non polar AA's will elute first |
|
|
Term
True or False
Relative mobility is characteristic of individual amino acids |
|
Definition
|
|
Term
True or False
In thin layer chromatography, the silica gel is polar and mobile. |
|
Definition
False
The silica gel is the stationary phase |
|
|
Term
| In thin layer chromatography, non-polar AAs will have _____ relative mobility (high/low) |
|
Definition
high
They interact the least with the polar silica gel, travel easily in the non-polar solvent |
|
|
Term
| What is the elution volume? |
|
Definition
| The amount of buffer required to move a compound through a column |
|
|
Term
| What is metal affinity chromatography? |
|
Definition
-protein is artificially reproduced with added His residues
-His tag protein binds tightly to the Ni2+ resin in a column
-all other proteins elute out
-imidazole is added which out-competes the His-tagged protein
-His-tag elutes last |
|
|
Term
| What ions do His-tagged proteins have a high affinity for? |
|
Definition
|
|
Term
| Why does imidazole out-compete the His-tag proteins? |
|
Definition
| because it has a similarly shaped side chain |
|
|
Term
| Gel filtration separates proteins on the basis of ________ |
|
Definition
|
|
Term
| In gel filtration, smaller proteins elute last because.... |
|
Definition
| They get trapped in the pores of the polymer and therefore take longer to elute |
|
|
Term
True or False
In gel filtration elution volume has a positive slope |
|
Definition
|
|
Term
| What speeds are required for ultracentrifugation of a protein sample? |
|
Definition
|
|
Term
| Sedimentation of a protein sample depends on ____ and ____ of the proteins |
|
Definition
|
|
Term
| Ultricentrifugation measures ________ of proteins in a sample |
|
Definition
|
|
Term
| What method would separate proteins based on size, shape and charge? |
|
Definition
|
|
Term
True or False
With polyacrylamide gel electrophoresis, separation is based on size |
|
Definition
|
|
Term
| What does SDS-PAGE stand for? |
|
Definition
| Sodium dodecyl sulfate polyacrylamide gel electrophoresis |
|
|
Term
| What is the isoelectric point? |
|
Definition
| the pH at which the net charge on a protein is zero |
|
|
Term
| What is isoelectric focussing and how are proteins separated? |
|
Definition
electrophoresis in a pH gradient
separation is based on charge |
|
|
Term
| In SDS-PAGE proteins take on an overall ______ charge and move _______ (to/from) the positive electrode? |
|
Definition
take on a negative charge
towards |
|
|
Term
True or False
In mass spectrometry, larger proteins will travel faster towards the charged detector |
|
Definition
|
|
Term
True or False
Velocity of a protein particle is directly related to the size of the protein |
|
Definition
False
Velocity depends inversely on mass |
|
|
