Chem. Ch 23
Card Set Information
Chem. Ch 23
Chem. Ch 23
The citric acid cycle operates under (aerobic or anaerobic) conditions only.
What cycle oxidizes the two-carbon acetyl group in acetyl CoA to 2 CO2?
Citric Acid Cycle
The citric acid cycle produces reduced coenzymes ____ and ____ and 1 ___ directly.
NADH and FADH2; ATP
In the citric acid cycle, acetyl (2 C) bonds to oxaloacetate (4 C) to form what?
Citrate (6 C)
In the citric acid cycle, oxidation and decarboxylation reactions convert citrate to what?
In the citric acid cycle, oxalocetate bonds with another what to repeat the cycle?
What combines with the 2-carbon acetyl group to form citrate?
Citrate isomerizes into what?
True or False: Citrate has a tertiary –OH group converted to a secondary –OH in isocitrate that can’t be oxidized.
False, it CAN be oxidized
Isocitrate undergoes what that removes carbon in the form of CO2?
Isocitrate oxidizes the –OH to a _____ releasing H+ and 2 e-.
Isocitrate provides H to reduce coenzyme NAD+ into what?
a-Ketoglutarate undergoes decarboxylation to form what?
a-Ketoglutarate produces a 4-carbon compound that bond to what?
a-Ketoglutarate provides H+ and 2 e- to reduce what into NADH?
Succinyl CoA undergoes hydrolysis what bond?
The thioester bond
What provides energy to add phosphate to GDP and form GTP because it’s a high-energy compound?
Succinate under goes what to lose 2 hydrogens and form a double bond?
Succinate provides 2 hydrogen to reduce FAD into what?
True or False: Fumarate undergoes hydration to add water to the double bond.
Fumarate is converted into what?
Malate undergoes what to form oxaloacetate with a C=O double bond?
Malate provides 2 hydrogen that reduce NAD+ into what?
NADH + H+
What cause the reaction rate for the citric acid cycle to increase?
It increases when low levels of ATP and NAD+ activate isocitrate dehydrogenase
What cause the reaction rate for the citric acid cycle to decrease?
It decrease when high levels of ATP or NADH inhibit citrate synthetase (first step in cycle)
What are oxidized and reduced as hydrogen and/or electrons are transferred from one carrier to the next?
What are 4 types of electron carriers?
FMN, Fe-S clusters, Coenzyme Q, and cytochromes
Electron carriers accept hydrogen and electrons from what?
The reduced coenzymes
Electron carries are oxidized and reduced to provide what?
Energy for the synthesis of ATP
FMN coenzyme contains what?
Flavin, ribitol, and phosphate
What accepts 2 H+ + 2 e- to form reduced coenzyme FMNH2?
What are groups of proteins containing iron ions and sulfide?
What accept electrons to reduce Fe3+ to Fe2+ , and lose electrons to re-oxidize Fe2+ to Fe3+ ?
Coenzyme Q (Q or CoQ) is a mobile electron carrier derived from what?
Coenzyme Q (Q or CoQ) is reduced when what?
The keto groups accept 2 H+ and 2 e-
Cytochromes (cyt) are proteins containing what?
Heme groups with iron ions
What is the abbreviation for cytochromes?
Electron transport uses what to transfer hydrogen ions and electrons from NADH and FADH2 until they combine with oxygen?
Electron transport forms what and produces what?
Forms H2O and produces ATP energy
In what system are electron carriers attached to the inner membrane of the mitochondrion?
The electron transport system
In the electron transport system, there are how many protein complexes?
In which NADH Dehydrogenase complex does hydrogen and electrons transfer from NADH to FMN, and then FMNH2 transfers hydrogen to Fe-S clusters and then to coenzyme Q reducing Q and regenerating FMN?
In Complex I of NADH Dehydrogenase, what is the overall reaction?
QH2, a mobile carrier, transfer hydrogen to Complex III
In Complex II of Succinate Dehydrogenase, there is a (higher or lower) energy level than Complex I.
In Complex II of Succinate Dehydrogenase, FADH2 transfers what to the coenzyme Q?
Hydrogen and Electrons
In Complex II of Succinate Dehydrogenase, Q is reduced into what and what is regenerated?
Q is reduced to QH2 and FAD is regenerated
What is QH2?
A mobile carrier, that transfers hydrogen to Complex III
In Complex III of CoQ-Cytochrome c Reducatase, electrons are transferred from QH2 to what?
Two Cyt b
In Complex III of CoQ-Cytochrome c Reducatse, each Cyt b (Fe3+) is reduced into what?
Cyt b (Fe2+)
In Complex III of CoQ-Cytochrome c Reducatase, what is regenerated?
In which complex are electrons transferred from Cyt b to Fe-S clusters, to Cyt C1, and to Cyt c, the second mobile carrier?
In Complex IV of Cytochrome c Oxidase, electrons are transferred from what --> to what --> to what?
Cyt c to Cyt a --> Cyt a to Cyt a3 --> Cty a3 to oxygen and H+ to form water