ACS BIOCHEMISTRY EXAM QUESTIONS AND ANSWERS UPDATED

ACS BIOCHEMISTRY EXAM QUESTIONS
AND ANSWERS UPDATED
Question 1
Step 9 of Glycolysis
Correct Answer
2-phosphoglycerate <--> Phosphoenolpyruvate (PEP)
Uses enolase enzyme.
Dehydration reaction (loss of water).



Question 2
Q (Ubiquinone/Coenzyme Q) Structure




Correct Answer



Question 3
ω-oxidation
Correct Answer
Similar to ß-oxidation but occurs simultaneously on both ends of the molecule.




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,Question 4
ΔGtransport Equation
Correct Answer
ΔGtransport = RTln([S]out / [S]in) + ZFΔΨ



Question 5
Enzyme Km and Substrate Concentration
Correct Answer
Most enzymes have a Km that is near the concentration of the substrate.



Question 6
Production of carbamoyl-phosphate
Correct Answer
NH4+ --> Carbamoyl Phosphate
Produced by carbamoyl phosphate synthetase I
2 ATP + HCO3 --> 2ADP + Pi



Question 7
Ramachandran Plot




Correct Answer
Shows favorable phi-psi angle combinations. 3 main "wells" for α-helices, ß-sheets,
and left-handed α-helices.




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,Question 8
Oxygenase Activity in Rubisco
Correct Answer
O2 competes with CO2 and reacts to form 2-phosphoglycerate



Question 9
Stage 3 of the Calvin Cycle
Correct Answer
Glyceraldehyde 3-phosphate --> Ribulose 1,5-bisphosphate
Requires 3 ATP and uses transketolase (TPP).
Only uses 8 of the 9 G3P's produced. One G3P is used to make starch/sucrose.



Question 10
pKa of Histidine R-group
Correct Answer
6.1



Question 11
Z-form DNA
Correct Answer
Left-handed helical form of DNA



Question 12
Ethanol Fermentation
Correct Answer
Pyruvate --> Acetalaldehyde --> Ethanol
Uses pyruvate decarboxylase (TPP) and alcohol dehydrogenase.
NADH --> CO2(TPP) + NAD+




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, Question 13
Step 7 of Glycolysis
Correct Answer
1,3-bisphosphoglycerate + ADP <--> 3-phosphoglycerate + ATP
Uses phosphoglycerate kinase enzyme.



Question 14
Regulation with fructose 2,6-bisphosphate
Correct Answer
Activates PFK-1 encouraging glycolysis. Inhibits FBPase-1 discouraging
gluconeogenesis



Question 15
Nitrogenase Complex
Correct Answer
Uses ATP hydrolysis and ATP binding to overcome activation energy. Has a FeMo
cofactor. Is an α2ß2 homodimer. Fixes N2 into NH4+



Question 16
Restriction Enzyme
Correct Answer
Cuts DNA at specific restriction sites.



Question 17
Zymogen
Correct Answer
An inactive precursor of an enzyme, activated by various methods (acid hydrolysis,
cleavage by another enzyme, etc.)




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