Midterm Prep Flashcards
Partition chromatography
▪ Particles of solid are chosen with a specific property, e.g. silica
gel has HO-Si-OH groups that can hydrogen-bond to polar
amino acids
▪ Stationary phase
Liquid solvent or buffer flows past the particles and is non-polar
Another format is thin layer chromatography
▪ Mobile phase
▪ Amino acids exchange (partition) between phases
▪ polar amino acids P spend more of their time hydrogen
bonded to silica and move slowly
Amino acids are identified by the volume of buffer needed
to move each through the column- elution volume
Ninhydrin
Sprayed on thin layer chromotography plate to identify amino acids which show up purple
Affinity Chromatography
- ligand (mlc with affinity for some amino acids) is in column
- proteins with afffinity for it bind and stay in column/bind tightly to it
- other proteins move faster and are eluted first
- high concentration of salt is added to displace and release the proteins bound to the ligand
Affinity Chromatography
- ligand (mlc with affinity for some amino acids) is in column
- proteins with afffinity for it bind and stay in column/bind tightly to it
- other proteins move faster and are eluted first
- high concentration of salt is added to displace and release the proteins bound to the ligand
Tag
A peptide or protein that binds a ligand with high affinity and specificity that is fused to the gene encoding target protein
Amino acid analysis
Includes separation of a mixture into components and detection of components of interest
Can be qualitative and quantitative and preparative
How are amino acids identified in partition chromatogra?
Illusion, volume concentration of amino acids is measured in each test cube, and the results are graphed
Ion exchange chromatography
This is charged residence as a stationary phase cationic exchanger contains negative groups, which band deposit of molecules and ions and I am exchanger and he’s positive. Which binds to negative groups/anions
How is illusion done in ion exchange chromatography
Hi ion concentration like a salt solution is inserted in common displace is the amino acid changing the pH to alter the charge on the iMac me know, I said, so no longer binds can also be done
SDS polyacrylamide gel
Smaller proteins move faster than larger ones
It separates proteins that differ in molecular weight
An electric field is used to move the proteins through a gel
SDS denatures the proteins
Urea
Weakens hydrophobic effect, allows protein to unfold/denature
Fluorodinitrobenzene
Can be used to study protein sequence and puts a tag on the first (N-terminal) amino acid dying it yellow to be recognized
At high pH, this group deprotonates and hydrolysis releases it
What factors cause certain amino acids to prefer beta
WYF VIT C
1) bulky amino acids prefer beta structure (WYF C)
2) awkward shaped/ branched amino acids also prefer it (VIT)
The binding pocket of chumptrypsin is lined with nonpolar amino acids
What is this an example of?
Hydrophobic effect
The binding pocket of chymotripsin is the right shape to fit a large amino acid
What is this an example of
This is an example of van der waals
Isoelectric point
The pH at which the net charge of the protein is zero
How many amino acids is each turn of the alpha helix
3.6
How many ampheres is each turn of the helix
5.4