Chapter 5 Flashcards
(13 cards)
What is an assay
A means of identifying a protein based on a unique property
Molecular exclusion chromatography
Separating proteins on basis of size
Ion exchange chromatography
Separating proteins on basis of net charge
Affinity chromatography
Based on attraction to a specific chemical group or molecule
Sedimentation coefficient
A measure of the rate of movement due to centrifugal force
Why do proteins precipitate at high salt concentration
High salt interacts with water then there is not enough water to interact with protein and precipitates
Water doesn’t want to be ordered
How does SDS destroy protein structure
Hydrophobic tail interupts hydrophobic interactions inside protein causing to unfold
Why is a protein least soluble at pI
Repulsion from protein molecules are minimal so large complexes for that are not soluble
Why does increasing salt increase protein solubility
At low salt conc it increases hydrophobic effect making protein push into Center and stabs loses protein which means more soluble
Salt binds to chargers preventing protein protein interaction
Where do you find small molecules on molecular exclusion chromatography and why
Top as they enter beads going slow
How do you calculate specific activity
Dividing total activity by total protein
Why do we use SDS
To make all same charge so it’s not dependent on charge and size
Do you find small or big molecule at bottom of centrifugue
Big
