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ACS BIOCHEMISTRY EXAM
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,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.
Homologs Shares 25% identity with another gene
Orthologs Similar genes in different organisms
Paralogs Similar "paired" genes in the same organism
Ramachandran Plot 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-.
, ß-sheet Either parallel or anti-parallel. Often twisted to increase strength.
Anti-parallel ß-sheet Alternating sheet directions (C & N-termini don't line-up). Has straight H-bonds.
Parallel ß-sheet 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 Breaks disulfide bonds.
α-keratin formed from 2 α-helices twisted around each other. "Coiled coil". Cross-linked
by disulfide bonds.
Collagen Repeating sequence of Gly-X-Pro. 3 stranded "coiled coil". Contains gly core.
Myoglobin 4° Structure Symmetric homodimer,
Hemoglobin 4° Structure Tetramer. Dimer of dimers. α2ß2 tetramer.
α/ß Protein Folding Less distinct areas of α and ß folding.
α+ß Protein Folding Two distinct areas of α and ß folding.
Mechanism of Denaturants Highly soluble, H-binding molecules. Stabilize protein backbone in water.
Allows denatured state to be stabilized.
Temperature Denaturation of Protein Midpoint of reaction is Tm.
Cooperative Protein Folding Folding transition is sharp. More reversible.
ACS BIOCHEMISTRY EXAM
Complete Chapters Solutions Manual
are Included
** Final Exam Questions With 100%
Correct Answers | Grade A+
** Guaranteed Pass
** Updated | New Version
,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.
Homologs Shares 25% identity with another gene
Orthologs Similar genes in different organisms
Paralogs Similar "paired" genes in the same organism
Ramachandran Plot 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-.
, ß-sheet Either parallel or anti-parallel. Often twisted to increase strength.
Anti-parallel ß-sheet Alternating sheet directions (C & N-termini don't line-up). Has straight H-bonds.
Parallel ß-sheet 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 Breaks disulfide bonds.
α-keratin formed from 2 α-helices twisted around each other. "Coiled coil". Cross-linked
by disulfide bonds.
Collagen Repeating sequence of Gly-X-Pro. 3 stranded "coiled coil". Contains gly core.
Myoglobin 4° Structure Symmetric homodimer,
Hemoglobin 4° Structure Tetramer. Dimer of dimers. α2ß2 tetramer.
α/ß Protein Folding Less distinct areas of α and ß folding.
α+ß Protein Folding Two distinct areas of α and ß folding.
Mechanism of Denaturants Highly soluble, H-binding molecules. Stabilize protein backbone in water.
Allows denatured state to be stabilized.
Temperature Denaturation of Protein Midpoint of reaction is Tm.
Cooperative Protein Folding Folding transition is sharp. More reversible.
