The Citric Acid Cycle - Video Tutorials & Practice Problems
Phase A - Citrate Formation Concept 1
Phase A - Citrate Formation Concept 2
Phase A - Citrate Formation Example 1
Phase B - Succinyl CoA Formation Concept 3
Phase B - Succinyl CoA Formation Concept 4
Phase B - Succinyl CoA Formation Concept 5
Phase B - Succinyl CoA Formation Concept 6
Phase B - Succinyl CoA Formation Example 2
Which enzyme oxidizes α-ketoglutarate in step 4 of the citric acid cycle?
isocitrate dehydrogenase
α-ketoglutarate oxidase
succinyl CoA synthase
α-ketoglutarate dehydrogenase
Which two steps of the citric acid cycle produce CO2?
1 and 3
3 and 4
2 and 4
2 and 3
Phase C - Oxaloacetate Regeneration Concept 7
Phase C - Oxaloacetate Regeneration Concept 8
Phase C - Oxaloacetate Regeneration Concept 9
Phase C - Oxaloacetate Regeneration Example 3
Phase C - Oxaloacetate Regeneration Concept 10
Phase C - Oxaloacetate Regeneration Concept 11
Phase C - Oxaloacetate Regeneration Example 4
Which one of the following enzymes catalyzes the addition of water to the C=C bond in fumarate?
Fumarate reductase
Malate synthase
Fumarase (Fumarate hydratase)
Malate dehydrogenase
How many final high-energy molecules are produced in phase C of the citric acid cycle?
2
4
1
3
Citric Acid Cycle Summary Concept 12
Citric Acid Cycle Summary Concept 13
Citric Acid Cycle Summary Concept 14
Citric Acid Cycle Summary Example 5
Complete the following net equation for one turn of the citric acid cycle.
Acetyl CoA + __H2O + 3 NAD+ + FAD + GDP + ____ ⭢ CoA + ___NADH + ___H+ + FADH2 + GTP + ___CO2
2 H2O; ATP ; 3 NADH; 3 H+; 1 CO2
3 H2O; Pi ; 3 NADH; 3 H+; 1 CO2
2 H2O; ATP ; 3 NADH; 3 H+; 2 CO2
1 H2O; Pi ; 3 NADH; 3 H+; 2 CO2
Which reaction of the citric acid cycle produces ATP directly?
Reaction 3
Reaction 5
Reaction 4
Reaction 6
Reaction 8
None of these
Remembering Citric Acid Cycle Concept 15
Remembering Citric Acid Cycle Concept 16
Remembering Citric Acid Cycle Example 6
Write the name for the substrate, enzyme, and product of reaction 6 of the citric acid cycle.
Succinyl CoA, succinyl CoA synthase, succinate
Succinate, succinate dehydrogenase, and fumarate
Succinyl CoA, succinate dehydrogenase, and fumarate
Fumarate, fumarase, and malate
Identify the two reactions that involve oxidation and decarboxylation.
Reactions 1 and 5
Reactions 3 and 6
Reactions 6 and 8
Reactions 2 and 7
Reactions 3 and 4
Write the name of the substrate and the enzyme of reaction 8 of the citric acid cycle.
Oxalate, oxalate oxidase
Malate, malate dehydrogenase
Succinate, succinate dehydrogenase
Fumarate, fumarase
What is the name of the enzyme for the reaction that produces a GTP molecule in the citric acid cycle?
Succinyl CoA synthase
Succinate dehydrogenase
α-ketoglutarate dehydrogenase
Fumarate hydratase
Which reactions of the citric acid cycle produce NADH?
Reactions 1, 2, and 8
Reactions 2, 4, and 6
Reactions 2, 5, and 7
Reactions 3, 4, and 8
Reactions 3, 4, and 6