ACS Biochemistry 2026 Exam – Fully Updated Questions
with Verified Correct Answers (A+ Rated) Chamberlain
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Henderson-Hasselbach Equation - ( ANSWER)-pH = pKa + log ([A-] / [HA])
FMOC Chemical Synthesis - ( ANSWER)-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) - ( ANSWER)-Changes soluble protein to solid precipitate. Protein
precipitates when the charges on the protein match the charges in the solution.
Size-Exclusion Chromatography - ( ANSWER)-Separates sample based on size with
smaller molecules eluting later.
Ion-Exchange Chromatography - ( ANSWER)-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 - ( ANSWER)-Beads are coated with a
carbon chain. Hydrophobic proteins stick better. Elute with non-H-bonding solvent
(acetonitrile).
Affinity Chromatography - ( ANSWER)-Attach a ligand that binds a protein to a bead. Elute
with harsh chemicals or similar ligand.
,SDS-PAGE - ( ANSWER)-Uses SDS. Gel is made from cross-linked polyacrylamide.
Separates based off of mass with smaller molecules moving faster. Visualized with
Coomassie blue.
SDS - ( ANSWER)-Sodium dodecyl sulfate. Unfolds proteins and gives them uniform
negative charge.
Isoelectric Focusing - ( ANSWER)-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) - ( ANSWER)-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) - ( ANSWER)-Reduces disulfide bonds.
Iodoacetate - ( ANSWER)-Adds carboxymethyl group on free -SH groups. Blocks disulfide
bonding.
Homologs - ( ANSWER)-Shares 25% identity with another gene
Orthologs - ( ANSWER)-Similar genes in different organisms
Paralogs - ( ANSWER)-Similar "paired" genes in the same organism
Ramachandran Plot - ( ANSWER)-Shows favorable phi-psi angle combinations. 3 main
"wells" for α-helices, ß-sheets, and left-handed α-helices.
,Glycine Ramachandran Plot - ( ANSWER)-Glycine can adopt more angles. (H's for R-
group).
Proline Ramachandran Plot - ( ANSWER)-Proline adopts fewer angles. Amino group is
incorporated into a ring.
α-helices - ( ANSWER)-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 - ( ANSWER)-Formed from added dipole moments of all hydrogen bonds in an
α-helix. N-terminus is δ+ and C-terminus is δ-.
ß-sheet - ( ANSWER)-Either parallel or anti-parallel. Often twisted to increase strength.
Anti-parallel ß-sheet - ( ANSWER)-Alternating sheet directions (C & N-termini don't line-up).
Has straight H-bonds.
Parallel ß-sheet - ( ANSWER)-Same sheet directions (C & N-termini line up). Has angled H-
bonds.
ß-turns - ( ANSWER)-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 - ( ANSWER)-Not highly structured. Not necessary highly flexible, but can
occasionally move. Very variable in sequence.
Circular Dichroism - ( ANSWER)-Uses UV light to measure 2° structure. Can be used to
measure destabilization.
, Disulfide-bonds - ( ANSWER)-Bonds between two -SH groups that form between 2° and 3°
structure.
ß-mercaptoethanol - ( ANSWER)-Breaks disulfide bonds.
α-keratin - ( ANSWER)-formed from 2 α-helices twisted around each other. "Coiled coil".
Cross-linked by disulfide bonds.
Collagen - ( ANSWER)-Repeating sequence of Gly-X-Pro. 3 stranded "coiled coil". Contains
gly core.
Myoglobin 4° Structure - ( ANSWER)-Symmetric homodimer,
Hemoglobin 4° Structure - ( ANSWER)-Tetramer. Dimer of dimers. α2ß2 tetramer.
α/ß Protein Folding - ( ANSWER)-Less distinct areas of α and ß folding.
α+ß Protein Folding - ( ANSWER)-Two distinct areas of α and ß folding.
Mechanism of Denaturants - ( ANSWER)-Highly soluble, H-binding molecules. Stabilize
protein backbone in water. Allows denatured state to be stabilized.
Temperature Denaturation of Protein - ( ANSWER)-Midpoint of reaction is Tm.
Cooperative Protein Folding - ( ANSWER)-Folding transition is sharp. More reversible.
with Verified Correct Answers (A+ Rated) Chamberlain
University | Instant Pdf Download
Henderson-Hasselbach Equation - ( ANSWER)-pH = pKa + log ([A-] / [HA])
FMOC Chemical Synthesis - ( ANSWER)-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) - ( ANSWER)-Changes soluble protein to solid precipitate. Protein
precipitates when the charges on the protein match the charges in the solution.
Size-Exclusion Chromatography - ( ANSWER)-Separates sample based on size with
smaller molecules eluting later.
Ion-Exchange Chromatography - ( ANSWER)-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 - ( ANSWER)-Beads are coated with a
carbon chain. Hydrophobic proteins stick better. Elute with non-H-bonding solvent
(acetonitrile).
Affinity Chromatography - ( ANSWER)-Attach a ligand that binds a protein to a bead. Elute
with harsh chemicals or similar ligand.
,SDS-PAGE - ( ANSWER)-Uses SDS. Gel is made from cross-linked polyacrylamide.
Separates based off of mass with smaller molecules moving faster. Visualized with
Coomassie blue.
SDS - ( ANSWER)-Sodium dodecyl sulfate. Unfolds proteins and gives them uniform
negative charge.
Isoelectric Focusing - ( ANSWER)-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) - ( ANSWER)-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) - ( ANSWER)-Reduces disulfide bonds.
Iodoacetate - ( ANSWER)-Adds carboxymethyl group on free -SH groups. Blocks disulfide
bonding.
Homologs - ( ANSWER)-Shares 25% identity with another gene
Orthologs - ( ANSWER)-Similar genes in different organisms
Paralogs - ( ANSWER)-Similar "paired" genes in the same organism
Ramachandran Plot - ( ANSWER)-Shows favorable phi-psi angle combinations. 3 main
"wells" for α-helices, ß-sheets, and left-handed α-helices.
,Glycine Ramachandran Plot - ( ANSWER)-Glycine can adopt more angles. (H's for R-
group).
Proline Ramachandran Plot - ( ANSWER)-Proline adopts fewer angles. Amino group is
incorporated into a ring.
α-helices - ( ANSWER)-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 - ( ANSWER)-Formed from added dipole moments of all hydrogen bonds in an
α-helix. N-terminus is δ+ and C-terminus is δ-.
ß-sheet - ( ANSWER)-Either parallel or anti-parallel. Often twisted to increase strength.
Anti-parallel ß-sheet - ( ANSWER)-Alternating sheet directions (C & N-termini don't line-up).
Has straight H-bonds.
Parallel ß-sheet - ( ANSWER)-Same sheet directions (C & N-termini line up). Has angled H-
bonds.
ß-turns - ( ANSWER)-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 - ( ANSWER)-Not highly structured. Not necessary highly flexible, but can
occasionally move. Very variable in sequence.
Circular Dichroism - ( ANSWER)-Uses UV light to measure 2° structure. Can be used to
measure destabilization.
, Disulfide-bonds - ( ANSWER)-Bonds between two -SH groups that form between 2° and 3°
structure.
ß-mercaptoethanol - ( ANSWER)-Breaks disulfide bonds.
α-keratin - ( ANSWER)-formed from 2 α-helices twisted around each other. "Coiled coil".
Cross-linked by disulfide bonds.
Collagen - ( ANSWER)-Repeating sequence of Gly-X-Pro. 3 stranded "coiled coil". Contains
gly core.
Myoglobin 4° Structure - ( ANSWER)-Symmetric homodimer,
Hemoglobin 4° Structure - ( ANSWER)-Tetramer. Dimer of dimers. α2ß2 tetramer.
α/ß Protein Folding - ( ANSWER)-Less distinct areas of α and ß folding.
α+ß Protein Folding - ( ANSWER)-Two distinct areas of α and ß folding.
Mechanism of Denaturants - ( ANSWER)-Highly soluble, H-binding molecules. Stabilize
protein backbone in water. Allows denatured state to be stabilized.
Temperature Denaturation of Protein - ( ANSWER)-Midpoint of reaction is Tm.
Cooperative Protein Folding - ( ANSWER)-Folding transition is sharp. More reversible.
