1.11-GlucoNeoGenesis Flashcards

1
Q

Do you find GlucoNeoGenesis in other organisms?

A

YES! A universal pathway…Anlimals, Plants, Fungi, and Microorganisms!

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2
Q

What are the four starting materials/precursors for Glucose?

A
  1. Lactate 2.Pyruvate 3. Glycerol 4. Amino Acids (18 out of 20)
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3
Q

When is GNG most active?

A

Inbetween meals, so during sleep and builds before breakfast, lunch, dinner

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4
Q

What are some of the main tissues that mainly depend on GNG? Think low blood supply again!

A

Brain, RBCs, Kidney, Testes

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5
Q

What is the cycle that Muscles break down glucose to lactate and Liver builds lactate to Glucose?

A

The Cori Cycle

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6
Q

What does the Cori Cycle do for blood pH?

A

It helps keep pH normal by getting Lactate (acidic) out of the blood

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7
Q

What two organs perform GNG? Which one does the Lion’s Share?

A

Liver & Kidney. Liver does the lions share

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8
Q

Is GNG simply a reversal of Glycolysis? What atet the 3 bypasses?

A

Nope, there are 3 irreversible steps that we will have to bypass! 1. Pyruvate–>PEP (Pyruvate Carboxylase) 2. Fructose-1,6-BisPhosphatase 3. Glucose-6-Phospatase

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9
Q

Are the Bypasses reversible?

A

No, they only go to GNG!

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10
Q

Where does each of the four starting materials enter GNG?

A

1.Lactate-Enters by being converted to Pyruvate before the first step 2. Amino Acids-a.some are converted to pyruvate b. some are converted to Oxaloacitate for step 2 3. Pyruvate-first step of GNG 4. Glycerol-enters late, in part 2 go GNG

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11
Q

What is the first step in the MAJOR pathway for Pyuvate to PEP? What Enzyme is used? Where does it happen? Is there ATP used?

A

1st step: Pyruvate–>Oxaloacetate Enzyme: Pyruvate Carboxylase. Occurs in the mitochondrial matrix. 1 ATP used

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12
Q

What is PC? What is it controlled by? What “type” of reaction does it catalyze?

A

Pyruvate Carboxylase. Controlled by HIGH Acetyl-CoA. ANA-PLE-ROTIC reaction

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13
Q

What is the Second step in the MAJOR pathway for pyruvate to PEP? What enzyme? Where?

A

2nd step: Oxaloacetate–>Malate. Enzyme: NADH Malate Dehydrogenase. Occurs in mitochondria (but now malate can exit!)

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14
Q

What is the third step in the MAJOR pathway (pyruvate to PEP? What enzyme? Where?

A

3rd Step: Malate –> Oxaloacetate Enzyme: NAD+ Malate Dehydrogenase. In cytosol

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15
Q

What is the simultaneous final step (so 3rd/4th step) of Pyruvate to PEP? What KEY enzyme is used? What form of energy is used?

A

3rd/4th step: Oxaloacetate–>PEP (Phospho-Enol-Pyruvate). KEY enzyme: PEP Carboxy-Kinase. Energy: 1 GTP

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16
Q

Why is the bypass shorter if lactate is the starting material?

A

It is more energetically favorable! (low NADH/NAD+ Ratio)

17
Q

What is Bypass #2? When is it in the grand scheme of things?

A

Fructose-1,6-Bisphosphate–>Fructose-6-Phospahte USING: Fructose-1,6-BisPhosphatase…3rd to LAST step of GNG

18
Q

What is Bypass #3? When is it in the grand scheme of things?

A

Glucose-6-Phosphate—> Glucose USING: Glucose-6-Phosphatase…LAST step of GNG

19
Q

What is the distribution of AAs that enter GNG via Pyruvate vs entering via CAC?

A

6 enter via pyruvate, the remaining 12 enter via CAC

20
Q

What are the two easy steps to introduce Glycerol into GNG?

A
  1. Glycerol–>Glycerol-3-Phosphate 2. Glycerol-3-Phosphate–>DHAP
21
Q

In terms of ATP: which is harder to do: GNG or Glycolysis?

A

GNG 6ATP investment (2NADH) vs Glycolysis: 2ATP investment

22
Q

How does Pyruvate Decarboxylation regulate GNG?

A

Lots of Acetyl CoA inhibits Pyruvate DeHydrogenase AND Stimulates Pyruvate Carboxylase

23
Q

What are the two regulators of GNG?

A

Pyruvate Carboxylase & PFK1/Fructose-1,6-BisPhospatase

24
Q

What is the GENERAL theme of PFK1/Fructose-1,6-BisPhosphatase regulation? What happens with presence of Low energy molecules? High energy molecules?

A

LOW energy molecules=Glycolysis! High energy mols present=GNG!