Podcast
Questions and Answers
What is the primary function of glyceraldehyde-3-phosphate dehydrogenase in the ED pathway?
What is the primary function of glyceraldehyde-3-phosphate dehydrogenase in the ED pathway?
What is the net yield of ATP molecules per glucose molecule in the ED pathway?
What is the net yield of ATP molecules per glucose molecule in the ED pathway?
What is the enzyme responsible for converting 2-phosphoglycerate to phosphoenolpyruvate (PEP)?
What is the enzyme responsible for converting 2-phosphoglycerate to phosphoenolpyruvate (PEP)?
What is the product of the substrate-level phosphorylation reaction catalyzed by phosphoglycerate kinase?
What is the product of the substrate-level phosphorylation reaction catalyzed by phosphoglycerate kinase?
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What is the primary function of NAD+ in the ED pathway?
What is the primary function of NAD+ in the ED pathway?
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What is the final product of the ED pathway?
What is the final product of the ED pathway?
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What is the reactant that donates a phosphate group to ADP in the final step of the ED pathway?
What is the reactant that donates a phosphate group to ADP in the final step of the ED pathway?
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In which step of the ED pathway is the enzyme phosphoglycerate mutase involved?
In which step of the ED pathway is the enzyme phosphoglycerate mutase involved?
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Which enzyme is absent in some microorganisms that use the Entner-Doudoroff pathway instead of glycolysis?
Which enzyme is absent in some microorganisms that use the Entner-Doudoroff pathway instead of glycolysis?
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What is the primary reason why the Entner-Doudoroff pathway is used by some bacteria instead of glycolysis?
What is the primary reason why the Entner-Doudoroff pathway is used by some bacteria instead of glycolysis?
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Which of the following microorganisms is a rare exception among Gram-positive bacteria that use the Entner-Doudoroff pathway?
Which of the following microorganisms is a rare exception among Gram-positive bacteria that use the Entner-Doudoroff pathway?
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What is the primary role of KDPG Aldolase in the Entner-Doudoroff pathway?
What is the primary role of KDPG Aldolase in the Entner-Doudoroff pathway?
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Which of the following organisms has been found to use the Entner-Doudoroff pathway as its main pathway for providing energy?
Which of the following organisms has been found to use the Entner-Doudoroff pathway as its main pathway for providing energy?
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What is the end product of glucose phosphorylation in the Entner-Doudoroff pathway?
What is the end product of glucose phosphorylation in the Entner-Doudoroff pathway?
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Which of the following compounds is a byproduct of the Entner-Doudoroff pathway?
Which of the following compounds is a byproduct of the Entner-Doudoroff pathway?
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What is the net ATP yield per glucose molecule in the Entner-Doudoroff pathway?
What is the net ATP yield per glucose molecule in the Entner-Doudoroff pathway?
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What is the net ATP yield per glucose molecule in the Entner-Doudoroff pathway?
What is the net ATP yield per glucose molecule in the Entner-Doudoroff pathway?
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What is the byproduct of the oxidation of glucose-6-phosphate in the Entner-Doudoroff pathway?
What is the byproduct of the oxidation of glucose-6-phosphate in the Entner-Doudoroff pathway?
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What enzyme is involved in the dehydration of 6-phosphogluconate to form 2 keto 3-deoxy-6-phosphogluconate?
What enzyme is involved in the dehydration of 6-phosphogluconate to form 2 keto 3-deoxy-6-phosphogluconate?
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What is the end product of the Entner-Doudoroff pathway that enters the TCA cycle?
What is the end product of the Entner-Doudoroff pathway that enters the TCA cycle?
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What enzyme is involved in the cleavage of KDPG to form pyruvate and glyceraldehyde-3-phosphate?
What enzyme is involved in the cleavage of KDPG to form pyruvate and glyceraldehyde-3-phosphate?
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What is the fate of glyceraldehyde-3-phosphate formed in the Entner-Doudoroff pathway?
What is the fate of glyceraldehyde-3-phosphate formed in the Entner-Doudoroff pathway?
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What is the enzyme responsible for the phosphorylation of glucose in the Entner-Doudoroff pathway?
What is the enzyme responsible for the phosphorylation of glucose in the Entner-Doudoroff pathway?
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What is the ATP requirement for the phosphorylation of glucose in the Entner-Doudoroff pathway?
What is the ATP requirement for the phosphorylation of glucose in the Entner-Doudoroff pathway?
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Study Notes
Entner-Doudoroff Pathway
- A metabolic pathway that catabolizes glucose to pyruvate, with a net yield of 1 ATP, 1 NADH, and 1 NADPH per glucose molecule.
- Uses unique enzymes, including 6-phosphogluconate dehydratase aldolase and 2-keto-deoxy-6-phosphogluconate (KDPG) aldolase, in addition to common metabolic enzymes.
Steps in the Entner-Doudoroff Pathway
- Step 1: Phosphorylation - Glucose is converted to glucose-6-phosphate by hexokinase enzyme, requiring ATP and Mg2+.
- Step 2: Oxidation - Glucose-6-phosphate is oxidized to 6-phosphogluconolactone by glucose-6-phosphate dehydrogenase, a NADP-dependent enzyme, yielding NADPH + H+.
- Step 3: Hydration - 6-Phosphogluconolactone is converted to 6-phosphogluconic acid by hydrolase.
- Step 4: Dehydration - 6-Phosphogluconate is dehydrated to form 2-keto-3-deoxy-6-phosphogluconate (KDPG) by 6-phosphogluconate dehydratase.
- Step 5: Cleavage of KDPG - KDPG is converted to pyruvate and glyceraldehyde-3-phosphate by KDPG aldolase.
- Step 6: Oxidation and Phosphorylation - Glyceraldehyde-3-phosphate is oxidized by NAD+ and phosphorylated by adding a free phosphate group, forming 1,3-bisphosphoglycerate.
- Step 7: Substrate-level phosphorylation - 1,3-Bisphosphoglycerate is converted to 3-phosphoglycerate by phosphoglycerate kinase (PGK), yielding ATP.
- Step 8: Isomerization - 3-Phosphoglyceric acid is converted to 2-phosphoglyceric acid by phosphoglyceromutase.
- Step 9: Dehydration - 2-Phosphoglycerate is converted to phosphoenolpyruvate (PEP) by enolase.
- Step 10: Substrate-level phosphorylation - PEP is converted to pyruvate by pyruvate kinase, yielding ATP.
Organisms that Use the Entner-Doudoroff Pathway
- Found in certain Gram-negative bacteria, such as Pseudomonas, Rhizobium, Azotobacter, and Agrobacterium.
- Rarely found in Gram-positive bacteria, with Enterococcus faecalis being an exception.
- Examples of bacteria that use the ED pathway include Pseudomonas, Azotobacter, Rhizobium, Agrobacterium, Escherichia coli, Enterococcus faecalis, Zymomonas mobilis, and Xanthomonas campestris.
- Also found in some cyanobacteria, ferns, algae, mosses, and plants, including Hordeum vulgare.
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Description
This quiz assesses your understanding of the Entner-Doudoroff pathway, a metabolic pathway that breaks down glucose to pyruvate, producing ATP, NADH, and NADPH. Learn about the distinct features and enzymes involved in this process.
