WGU BIOCHEMISTRY OA PRACTICE EXAMINATION 2026 QUESTIONS WITH ANSWERS GRADED A+

WGU BIOCHEMISTRY OA PRACTICE
EXAMINATION 2026 QUESTIONS
WITH ANSWERS GRADED A+

◍ true.
Answer: T/F: The majority of the reactions of the urea cycle occur in the
cytosol.
◍ Henderson-Hasselbach Equation.
Answer: pH = pKa + log ([A-] / [HA])
◍ false.
Answer: T/F: The majority of the reactions of the urea cycle occur in the
mitochondrial matrix.
◍ 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.
◍ false.
Answer: T/F: FADH2 yields 2.5 ATP molecules after donating electrons and
hydrogen atoms to the ETC.
◍ Salting Out (Purification).
Answer: Changes soluble protein to solid precipitate. Protein precipitates
when the charges on the protein match the charges in the solution.
◍ 2.5 ATP per NADH.
Answer: How many ATP molecules does NADH yield after donating
electrons and hydrogen atoms to the electron transfer chain (ETC)?
◍ 1.5 ATP per FADH2.
Answer: How many ATP molecules does FADH2 yield after donating

, electrons and hydrogen atoms to the electron transfer chain (ETC)?
◍ Size-Exclusion Chromatography.
Answer: Separates sample based on size with smaller molecules eluting
later.
◍ true.
Answer: T/F: ATP is invested in the urea cycle.
◍ false.
Answer: T/F: There are 5 complexes associated with the ETC.
◍ 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).
◍ false.
Answer: T/F: In the production of ATP via ATP synthase, the H+ ions move
from the mitochondrial matrix to the intermembrane space.
◍ Affinity Chromatography.
Answer: Attach a ligand that binds a protein to a bead. Elute with harsh
chemicals or similar ligand.
◍ true.
Answer: T/F: In the production of ATP via ATP synthase, the H+ ions move
from the intermembrane space to the mitochondrial matrix.
◍ 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.
◍ ornithine, arginine, and aspartate.
Answer: What amino acids are involved in the urea cycle?
◍ 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.
◍ malate.
Answer: Fumarate reenters the mitochondrion as
◍ ability to hydrogen bonds with water and its high density of nitrogen in a
small molecule.
Answer: Urea is useful for excreting nitrogen from cells due to its
◍ fumarate.
Answer: Which component of the urea cycle is also a member of the CAC?
◍ Homologs.
Answer: Shares 25% identity with another gene
◍ NH4+ (amine group).
Answer: Oxidative deamination results in the removal of ___ from amino
acids.