Glycolysis, Gluconeogenesis, and the

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Chapter 14
Glycolysis, Gluconeogenesis, and the Pentose
Phosphate Pathway Part 2 Gluconeogenesis and
PPP
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Gluconeogenesis and PPP Learning Goals.

• Know
• Entry to gluconeogenesis.
• Glycolysis backwards which enzymes are at Eq
  and those that are the drivers.
• What makes some amino acids glucogenic.
• Pentose Phosphate Pathway entry by glucose-6-P
  and transaldolases, transketolases.
• Why the PPP is a web pathway.

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Gluconeogenesis Forms Sugars from Other
Metabolites
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Going Forwards and Backwards
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The Beginning of Gluconeogenesis
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Pyruvate Carboxylase
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PEP Carboxykinase
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Pyruvate Actually Has Two Ways to PEP
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The End of Gluconeogenesis
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Gluconeogenesis Energetics
EOC Problem 21 overall energetics of Glycolysis
and Gluconeogenesis. EOC Problem 22 Concept of
a Futile Cycle.
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Pentose Phosphate Pathway Beginning
aromatic amino acids His
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NADPH and Oxygen Toxicity
SuperOxide Dismutase
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PPP Beginning from Glucose-6-Phosphate
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Lactonase
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6-Phosphogluconate DH
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Phosphopentose Isomerase (not an Epimerase)
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Ribose-5-Phosphate Epimerase
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PPP the Web like Pathway Stuck onto the Side of
Glycolysis
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PPP Transketolases transfer 2 Carbon units
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PPP Transketolases transfer 2 Carbon units
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PPP Transaldolases transfer 3 Carbon units
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Another Transketolase
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PPP Arranged to Oxidize Glucose (6 in and 5 out)
6 Glucose-6-P
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Control of PPP by NADPH
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PPP Functions

1. Produce Ribose-5-P for Nucleotide Synthesis
2. Produce Ribose-5-P for His Synthesis
3. Produce Erythrose-4P for Trp, Tyr, Phe Synthesis
   WYF
4. Can Completely Oxidize Glucose
5. Source of NADPH (Biosynthesis, Oxygen Killing
   System)
6. Can be Rearranged to Calvin Cycle Fix CO2
7. Other Specialized Reasons (Heterofermenters, etc.
   mainly in prokaryotes)

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Things to Know and Do Before Class

1. Entry to gluconeogenesis.
2. Glycolysis backwards which enzymes are at Eq
   and those that are the drivers.
3. What makes some amino acids glucogenic.
4. Pentose Phosphate Pathway entry by glucose-6-P
   and transaldolases, transketolases.
5. Why the PPP is a web pathway.
6. EOC Problems 21, 22, 25 27.