MCB 2000 Final Exam 4 Questions
with Already Passed Solutions Graded
A+ 2025-2026 Verified.
how many oxidation reduction reactions are in the TCA cycle - Answer 4
where can we get acetyl CoA from - Answer fatty acids, ketones, glucose to pyruvate, and
ethanol
in the TCA cycle, what is oxidized to carbon dioxide - Answer acetyl CoA
phase 1 of the TCA cycle - Answer oxidation of acetyl CoA to CO2
ordered binding in TCA cycle - Answer oxaloacetate MUST bind first because it performs
conformational changes before acetyl CoA can bind to citrate synthase
enzyme that performs condensation reaction in the TCA cycle while breaking thioester bond -
Answer citrate synthase
isomerization enzyme in TCA cycle - Answer aconitase
rate limiting step in TCA cycle - Answer isocitrate dehydrogenase performs oxidative
decarboxylation of isocitrate to alpha-keotglutarate (releases NADH + CO2)
2nd oxidative decarboxylation enzyme in TCA cycle - Answer alpha-ketoglutarate
dehydrogenase
ATP producing step in TCA cycle by breaking thioester bond - Answer succinyl CoA to
succinate by succinyl CoA Synthase
phase 2 of TCA cycle - Answer regeneration of OAA
succinate dehydrogenase - Answer succinate to fumurate
, problem with malate dehydrogenase reaction - Answer malate is favored so the reaction is
coupled by the hydrolysis of thioester bond by citrate synthase
regulation of citrate synthase - Answer OAA substrate concentration & negative feedback by
product citrate
why does citrate have to be isomerized by aconitase - Answer citrate is poor substrate for
oxidation, secondary -OH group on isocitrate allows for oxidation (involves dehydration followed
by hydration)
intermediate in isocitrate oxidation decarboxylation reaction - Answer oxalosuccinate
describe the oxidation done by isocitrate dehydrogenase - Answer oxidation of alcohol group
to keto body
why is isocitrate dehydrogenase the rate limiting enzyme - Answer links to the electron
transport pathway because it makes NADH, rate of formation of alpha-ketoglutarate determines
rate of TCA cycle
negative allosteric regulation of isocitrate dehydrogenase - Answer ATP and NADH
positive allosteric regulation of isocitrate dehydrogenase - Answer AMP and NAD+
what enzyme is nearly identical to pyruvate dehydrogenase - Answer alpha-ketoglutarate
dehydrogenase
5 coenzymes of alpha-ketogulatarate dehydrogenase - Answer TPP, CoASH, lipioc acid, NAD+,
and FAD
substrate level phosphorylation in TCA cycle is performed by this enzyme - Answer succinyl
CoA synthase, produces ATP or GTP
type of reaction by succinate dehydrogenase - Answer dehydrogenation
with Already Passed Solutions Graded
A+ 2025-2026 Verified.
how many oxidation reduction reactions are in the TCA cycle - Answer 4
where can we get acetyl CoA from - Answer fatty acids, ketones, glucose to pyruvate, and
ethanol
in the TCA cycle, what is oxidized to carbon dioxide - Answer acetyl CoA
phase 1 of the TCA cycle - Answer oxidation of acetyl CoA to CO2
ordered binding in TCA cycle - Answer oxaloacetate MUST bind first because it performs
conformational changes before acetyl CoA can bind to citrate synthase
enzyme that performs condensation reaction in the TCA cycle while breaking thioester bond -
Answer citrate synthase
isomerization enzyme in TCA cycle - Answer aconitase
rate limiting step in TCA cycle - Answer isocitrate dehydrogenase performs oxidative
decarboxylation of isocitrate to alpha-keotglutarate (releases NADH + CO2)
2nd oxidative decarboxylation enzyme in TCA cycle - Answer alpha-ketoglutarate
dehydrogenase
ATP producing step in TCA cycle by breaking thioester bond - Answer succinyl CoA to
succinate by succinyl CoA Synthase
phase 2 of TCA cycle - Answer regeneration of OAA
succinate dehydrogenase - Answer succinate to fumurate
, problem with malate dehydrogenase reaction - Answer malate is favored so the reaction is
coupled by the hydrolysis of thioester bond by citrate synthase
regulation of citrate synthase - Answer OAA substrate concentration & negative feedback by
product citrate
why does citrate have to be isomerized by aconitase - Answer citrate is poor substrate for
oxidation, secondary -OH group on isocitrate allows for oxidation (involves dehydration followed
by hydration)
intermediate in isocitrate oxidation decarboxylation reaction - Answer oxalosuccinate
describe the oxidation done by isocitrate dehydrogenase - Answer oxidation of alcohol group
to keto body
why is isocitrate dehydrogenase the rate limiting enzyme - Answer links to the electron
transport pathway because it makes NADH, rate of formation of alpha-ketoglutarate determines
rate of TCA cycle
negative allosteric regulation of isocitrate dehydrogenase - Answer ATP and NADH
positive allosteric regulation of isocitrate dehydrogenase - Answer AMP and NAD+
what enzyme is nearly identical to pyruvate dehydrogenase - Answer alpha-ketoglutarate
dehydrogenase
5 coenzymes of alpha-ketogulatarate dehydrogenase - Answer TPP, CoASH, lipioc acid, NAD+,
and FAD
substrate level phosphorylation in TCA cycle is performed by this enzyme - Answer succinyl
CoA synthase, produces ATP or GTP
type of reaction by succinate dehydrogenase - Answer dehydrogenation
