Exam (elaborations)
ACS BIOCHEMISTRY EXAM WITH COMPLETE SOLUTIONS LATEST UPDATE
- Course
- Institution
ACS BIOCHEMISTRY EXAM WITH COMPLETE SOLUTIONS LATEST UPDATE
[Show more]
Seller
Follow
Schoolflix
Reviews received
Content preview
ACS BIOCHEMISTRY EXAM WITHCOMPLETE SOLUTIONS LATEST UPDATE
Henderson-Hasselbach Equation - correct answers pH = pKa + log ([A-] / [HA])
FMOC Chemical Synthesis - correct answers 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) - correct answers Changes soluble protein to solid
precipitate. Protein precipitates when the charges on the protein match the
charges in the solution.
Size-Exclusion Chromatography - correct answers Separates sample based on size
with smaller molecules eluting later.
Ion-Exchange Chromatography - correct answers 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 - correct answers Beads are coated
with a carbon chain. Hydrophobic proteins stick better. Elute with non-H-bonding
solvent (acetonitrile).
,Affinity Chromatography - correct answers Attach a ligand that binds a protein to a
bead. Elute with harsh chemicals or similar ligand.
SDS-PAGE - correct answers Uses SDS. Gel is made from cross-linked
polyacrylamide. Separates based off of mass with smaller molecules moving faster.
Visualized with Coomassie blue.
SDS - correct answers Sodium dodecyl sulfate. Unfolds proteins and gives them
uniform negative charge.
Isoelectric Focusing - correct answers 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) - correct answers 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) - correct answers Reduces disulfide bonds.
Iodoacetate - correct answers Adds carboxymethyl group on free -SH groups.
Blocks disulfide bonding.
Homologs - correct answers Shares 25% identity with another gene
,Orthologs - correct answers Similar genes in different organisms
Paralogs - correct answers Similar "paired" genes in the same organism
Ramachandran Plot - correct answers Shows favorable phi-psi angle combinations.
3 main "wells" for α-helices, ß-sheets, and left-handed α-helices.
Glycine Ramachandran Plot - correct answers Glycine can adopt more angles. (H's
for R-group).
Proline Ramachandran Plot - correct answers Proline adopts fewer angles. Amino
group is incorporated into a ring.
α-helices - correct answers 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 - correct answers Formed from added dipole moments of all hydrogen
bonds in an α-helix. N-terminus is δ+ and C-terminus is δ-.
ß-sheet - correct answers Either parallel or anti-parallel. Often twisted to increase
strength.
Anti-parallel ß-sheet - correct answers Alternating sheet directions (C & N-termini
don't line-up). Has straight H-bonds.
, Parallel ß-sheet - correct answers Same sheet directions (C & N-termini line up).
Has angled H-bonds.
ß-turns - correct answers 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 - correct answers Not highly structured. Not necessary highly flexible, but
can occasionally move. Very variable in sequence.
Circular Dichroism - correct answers Uses UV light to measure 2° structure. Can be
used to measure destabilization.
Disulfide-bonds - correct answers Bonds between two -SH groups that form
between 2° and 3° structure.
ß-mercaptoethanol - correct answers Breaks disulfide bonds.
α-keratin - correct answers formed from 2 α-helices twisted around each other.
"Coiled coil". Cross-linked by disulfide bonds.
Collagen - correct answers Repeating sequence of Gly-X-Pro. 3 stranded "coiled
coil". Contains gly core.
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 Schoolflix. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $16.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
72964 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now