Krebs Cycle Flashcards
What is the Krebs cycle?
Provides electrons or high energy molecules to the electron transport chain
Occurs in the mitochondria for eukaryotes and in the cytoplasm for prokaryotes
Who discovered the Krebs cycle?
Hans Adolf Krebs
Is the Krebs cycle aerobic or anaerobic?
Aerobic
What is the first step of the Krebs cycle?
Pyruvate is decarboxylated by pyruvate dehydrogenase
Forms acetyl CoA and carbon dioxide
What is the second step of Krebs cycle?
CoA methyl group of acetyl CoA and carbonyl group of oxaloacetate on carbon-5 join together and form citryl CoA
Citryl CoA is hydrolyzed and produce free CoA and citrate
What is the third step of the Krebs cycle?
Citrate is dehydrated by aconitase
Forms cis-aconitase
What is the fourth step of the Krebs cycle?
Isocitrate is dehydrated by isocitrate dehydrogenase forms oxalosuccinate
Oxalosuccinate is decarboxylated and forms a-ketoglutarate
What is the fifth step of the Krebs cycle?
A-ketoglutarate is decarboxylated by a-ketoglutarate dehydrogenase
Forms succinyl-CoA and carbon dioxide
Reduces NAD+ to NADH
What is the sixth step of the Krebs cycle?
Succinyl-CoA is cleaved by succinyl-CoA synthetase
Forms succinate and free CoA
GTP is transferred to phosphate group and forms ADP
What is the seventh step of the Krebs cycle?
Succinate is dehydrated by succinate dehydrogenase
Forms fumarate
FAD accepts a H+
Forms FADH2
What is the eighth step of the Krebs cycle?
Fumarate is hydrated by fumarase hydrogenase forms L-malate
What is the ninth step of the Krebs cycle?
L-malate is dehydrated by L-malate dehydrogenase
Forms oxaloacetate
NAD+ is reduced to NADH
What are the products of the Krebs cycle?
3 NADH
1 FADH2
1 GTP
2CO2
What steps of the Krebs cycle are reversible?
3 and 8
