CA cycle Flashcards
What is the first reaction of CA cycle?
Acetyl Coa + oxaloacetate into citrate by citrate synthase
What is the second reaction of CA cycle?
Citrate into isocitrate by aconitase
What is the third reaction of the CA cycle?
Isocitrate into alpha-ketogluterate by isocitrate dehydrogenase using NAD
What are the other products of the third reaction of the CA cycle?
NADH + H
CO2
What is the fourth reaction of the CA cycle?
Alpha-ketogluterate to Succinyl CoA using alpha-ketogluterate dehydrogenase using CoASH and NAD
What are the other products of the fourth reaction of the CA cycle?
NADH + H
CO2
What are the coenzymes of alpha-ketogluterate dehydrogenase?
TPP
Lipoamide
CoA
What is the fifth reaction of the CA cycle?
Succinyl CoA into Succinate by succinyl CoA synthetase using GDP and Pi
What are the other products of fifth reaction of the CA cycle?
CoASH
GTP
What is the sixth reaction of the CA cycle?
Succinate to fumarate by succinate dehydrogenase using FAD
What is the other product of the sixth reaction of CA cycle?
FADH2
What is the seventh reaction of the CA cycle?
Fumarate to Malate using fumarase
What is the eighth and final reaction of the CA cycle?
Malate into oxaloacetate by malate dehydrogenase using NAD
What is the other product of the final step of the CA cycle?
NADH + H
What inhibits aconitase?
Fluorocitrate
How is fluorocitrate formed?
Fluoracetate (poison) condenses with oxaloacetate
What poison inhibits alpha-ketoglutarate dehydrogenase?
Arsenite
What enzyme of the CA cycle is bound to the IMM?
Succinate dehydrogenase
What are the typical regulatory enzymes of the CA cycle?
Citrate synthase
Isocitrate dehydrogenase
Alpha-ketoglutarate dehydrogenase
What allosterically inhibits citrate synthase?
ATP
Long chain fatty acyl CoA
What allosterically stimulates isocitrate dehydrogenase?
ADP
What allosterically inhibits isocitrate dehydrogenase?
NADH
ATP
What inhibits alpha-ketoglutarate dehydrogenase?
Succinyl CoA
NADH
High energy charge (high level of ATP in cell)
What inhibits succinyl dehydrogenase?
Oxaloacetate
What does the availability of oxaloacetate depend on?
NADH/NAD ratio that affects malate dehydrogenase
What enzymes are affected by arsenic poisoning?
PDH complex
alpha-ketoglutarate dehydrogenase
Alpha ketoacid dehydrogenase
What part of the enzyme is affected by arsenic poisoning?
-SH group of lipoic acid
How much NADH and FADH2 are produced by the CA cycle per glucose?
6 NADH
2 FADH
How much energy is produced for each NADH that goes through ETC?
2.5 ATP
How much energy is produced for each FADHs that goes through ETC?
1.5 ATP
How much energy is produced by the CA cycle for each glucose?
20 ATP
How much energy is produced for each glucose from glycolysis through TCA cycle?
32 ATP
Other than energy production, why else is the CA cycle important?
Major pathway for gluconeogenesis, AA synthesis, and fatty acid synthesis
What does amphibolic mean?
Functions as both oxidative/metabolic and synthetic/anabolic
What are sources of acetyl CoA?
Palmitate
Acetoacetate
Pyruvate
Ethanol
What is the part of the CA cycle that is used in gluconeogenesis?
Oxaloacetate
What is the part of the CA cycle used in fatty acid synthesis?
Acetyl CoA
What is the vitamin found in FAD?
Riboflavin
What is the vitamin found in NAD?
Niacin
What is pantothenic acid a part of as a coenzyme?
Coenzyme A
How is biotin used in the CA cycle?
CO2 fixation reaction for oxaloacetate concentration
What is anaplerosis?
Replenishing CA cycle intermediates