ACS BIOCHEMISTRY EXAM Questions and Correct Answers the Latest Update
3 views 0 purchase
Course
ACS
Institution
ACS
Henderson-Hasselbach Equation
pH = pKa + log ([A-] / [HA])
FMOC Chemical Synthesis
Used in synthesis of a growing amino acid chain to a polystyrene bead. FMOC is
used as a protecting group on the N-terminus.
Salting Out (Purification)
Changes soluble protein to solid precipitate. Protein ...
ACS BIOCHEMISTRY EXAM
Questions and Correct Answers the
Latest Update
Henderson-Hasselbach Equation
✓ pH = pKa + log ([A-] / [HA])
FMOC Chemical Synthesis
✓ Used in synthesis of a growing amino acid chain to a polystyrene bead. FMOC is
used as a protecting group on the N-terminus.
Salting Out (Purification)
✓ Changes soluble protein to solid precipitate. Protein precipitates when the charges
on the protein match the charges in the solution.
Size-Exclusion Chromatography
✓ Separates sample based on size with smaller molecules eluting later.
Ion-Exchange Chromatography
✓ Separates sample based on charge. CM attracts +, DEAE attracts -. May have
repulsion effect on like charges. Salt or acid used to remove stuck proteins.
Hydrophobic/Reverse Phase Chromatography
✓ Beads are coated with a carbon chain. Hydrophobic proteins stick better. Elute with
non-H-bonding solvent (acetonitrile).
✓ Attach a ligand that binds a protein to a bead. Elute with harsh chemicals or similar
ligand.
SDS-PAGE
✓ Uses SDS. Gel is made from cross-linked polyacrylamide. Separates based off of mass
with smaller molecules moving faster. Visualized with Coomassie blue.
SDS
✓ Sodium dodecyl sulfate. Unfolds proteins and gives them uniform negative charge.
Isoelectric Focusing
✓ Variation of gel electrophoresis where protein charge matters. Involves electrodes
and pH gradient. Protein stops at their pI when neutral.
FDNB (1-fluoro-2,3-dinitrobenzene)
✓ FDNB reacts with the N-terminus of the protein to produce a 2,4-dinitrophenol
derivative that labels the first residue. Can repeat hydrolysis to determine sequential
amino acids.
DTT (dithiothreitol)
✓ Reduces disulfide bonds.
Iodoacetate
✓ Adds carboxymethyl group on free -SH groups. Blocks disulfide bonding.
✓ Shows favorable phi-psi angle combinations. 3 main "wells" for α-helices, ß-sheets,
and left-handed α-helices.
Glycine Ramachandran Plot
✓ Glycine can adopt more angles. (H's for R-group).
Proline Ramachandran Plot
✓ Proline adopts fewer angles. Amino group is incorporated into a ring.
α-helices
✓ Ala is common, Gly & Pro are not very common. Side-chain interactions every 3 or
4 residues. Turns once every 3.6 residues. Distance between backbones is 5.4Å.
Helix Dipole
✓ Formed from added dipole moments of all hydrogen bonds in an α-helix. N-terminus
is δ+ and C-terminus is δ-.
✓ Same sheet directions (C & N-termini line up). Has angled H-bonds.
ß-turns
✓ Tight u-turns with specific phi-psi angles. Must have gly at position 3. Proline may
also be at ß-turn because it can have a cis-omega angle.
Loops
✓ Not highly structured. Not necessary highly flexible, but can occasionally move. Very
variable in sequence.
Circular Dichroism
✓ Uses UV light to measure 2° structure. Can be used to measure destabilization.
Disulfide-bonds
✓ Bonds between two -SH groups that form between 2° and 3° structure.
ß-mercaptoethanol
Examify | Smart Grades | Latest update
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Examify. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.49. You're not tied to anything after your purchase.
