WGU BIOCHEMISTRY OA 2025/2026 QUESTIONS WITH
ANSWERS RATED A+
✔✔Mismatch repair - ✔✔-happens in mistakes with DNA replication
-DNA polymerase proofreads to see if make a right choice, but makes a mistake.
-remove big section of damage and replace all of it
✔✔Homologous recombination - ✔✔-use 2nd copy of the DNA to copy back the correct
info
- double strand (cut DNA in 2), break
✔✔Non-homologous end-joining - ✔✔-happens before DNA replication
-trim the ends-stuck back together
✔✔PCR - ✔✔-DNA replication in a test tube
-Denature, Anneal, Elongation, Repeat
✔✔Denature - ✔✔-step 1 of PCR
-increase heat to separate the DNA
✔✔Anneal - ✔✔-step 2 of PCR
-use DNA primers that match the gene to find only the gene we want (ex: to find BRCA
gene)
✔✔Elongation - ✔✔-step 3 of PCR
-use DNA polymerase to make copies of our genes
✔✔Which ingredients/molecules are required to set up a PCR? - ✔✔-DNA polymerase
(elongation)
-DNA nucleotides (dNTPs)
-primers (annealing)
-template DNA (patient DNA)
✔✔DNA polymerase always makes strands : - ✔✔5'-3'
✔✔What breaks ionic bonds? - ✔✔-pH changes
-salt changes
✔✔What breaks hydrogen bonds? - ✔✔-pH and salt changes
(Disulfide bonds broken by reducing agent)
✔✔What breaks hydrophobic bonds? - ✔✔Heat
✔✔Types of bonds from strongest to weakest - ✔✔-disulfide bond
, -ionic bond
-hydrogen bond
-hydrophobic bond
✔✔Which bond is weakest, but have most influence on protein structure because of
how many there are? - ✔✔Hydrophobic bond
✔✔Quaternary Structure - ✔✔-only some proteins will get here
-2 or more subunits
-proteins
-Polypeptides
(Example= myoglobin and hemoglobin)
✔✔Hydrolysis - ✔✔Broken peptide bonds
✔✔Chaperones - ✔✔Help fold proteins
✔✔Denature - ✔✔-have an environmental change that causes a protein to misfold or
unfold.
-breaking side change & secondary structure bonds
-disulfide=reducing agent
-ionic=pH or salt change
-hydrophobic=heat change
✔✔Degradation - ✔✔Break peptide bonds
(Hydrolysis)
✔✔Aggregation - ✔✔-proteins clump together in abnormal way (d/t hydrophobic
interactions)
✔✔Enzymes - ✔✔-functional proteins
-catalysts
-reusable (can be recycled!)
-specific
-induced fit
-work like assembly line (enzyme pathway)
✔✔Feedback inhibition - ✔✔-stop the enzyme "assembly line" because we have too
much "product"
-happens naturally to maintain homeostasis
✔✔Competitive inhibition - ✔✔-medicine/drugs
-competitive inhibitor will bind to active site to prevent substrate from binding
-(overcome inhibition by adding more substrate)
ANSWERS RATED A+
✔✔Mismatch repair - ✔✔-happens in mistakes with DNA replication
-DNA polymerase proofreads to see if make a right choice, but makes a mistake.
-remove big section of damage and replace all of it
✔✔Homologous recombination - ✔✔-use 2nd copy of the DNA to copy back the correct
info
- double strand (cut DNA in 2), break
✔✔Non-homologous end-joining - ✔✔-happens before DNA replication
-trim the ends-stuck back together
✔✔PCR - ✔✔-DNA replication in a test tube
-Denature, Anneal, Elongation, Repeat
✔✔Denature - ✔✔-step 1 of PCR
-increase heat to separate the DNA
✔✔Anneal - ✔✔-step 2 of PCR
-use DNA primers that match the gene to find only the gene we want (ex: to find BRCA
gene)
✔✔Elongation - ✔✔-step 3 of PCR
-use DNA polymerase to make copies of our genes
✔✔Which ingredients/molecules are required to set up a PCR? - ✔✔-DNA polymerase
(elongation)
-DNA nucleotides (dNTPs)
-primers (annealing)
-template DNA (patient DNA)
✔✔DNA polymerase always makes strands : - ✔✔5'-3'
✔✔What breaks ionic bonds? - ✔✔-pH changes
-salt changes
✔✔What breaks hydrogen bonds? - ✔✔-pH and salt changes
(Disulfide bonds broken by reducing agent)
✔✔What breaks hydrophobic bonds? - ✔✔Heat
✔✔Types of bonds from strongest to weakest - ✔✔-disulfide bond
, -ionic bond
-hydrogen bond
-hydrophobic bond
✔✔Which bond is weakest, but have most influence on protein structure because of
how many there are? - ✔✔Hydrophobic bond
✔✔Quaternary Structure - ✔✔-only some proteins will get here
-2 or more subunits
-proteins
-Polypeptides
(Example= myoglobin and hemoglobin)
✔✔Hydrolysis - ✔✔Broken peptide bonds
✔✔Chaperones - ✔✔Help fold proteins
✔✔Denature - ✔✔-have an environmental change that causes a protein to misfold or
unfold.
-breaking side change & secondary structure bonds
-disulfide=reducing agent
-ionic=pH or salt change
-hydrophobic=heat change
✔✔Degradation - ✔✔Break peptide bonds
(Hydrolysis)
✔✔Aggregation - ✔✔-proteins clump together in abnormal way (d/t hydrophobic
interactions)
✔✔Enzymes - ✔✔-functional proteins
-catalysts
-reusable (can be recycled!)
-specific
-induced fit
-work like assembly line (enzyme pathway)
✔✔Feedback inhibition - ✔✔-stop the enzyme "assembly line" because we have too
much "product"
-happens naturally to maintain homeostasis
✔✔Competitive inhibition - ✔✔-medicine/drugs
-competitive inhibitor will bind to active site to prevent substrate from binding
-(overcome inhibition by adding more substrate)
