In gluconeogenesis, pyruvate is converted to PEP in two reactions. These reactions include an initial carboxylation...

In gluconeogenesis, pyruvate is converted to PEP in two reactions. These reactions include an initial carboxylation followed by a decarboxylation in the second reaction. Based on these two reactions, you would assume that if radio-labeled 14CO2 was present in the reactions, it would not be incorporated into PEP. However, when 14CO2 is present with rat liver cells 14C slowly begins to appear in PEP and eventually on carbons 3 and 4 of glucose. Diagram a series of reactions that would explain this observation. You need to clearly show the location of the radiolabeled 14C in all reactions and indicate any changes in localization with the cells

Expert Solution

queen_honey_blossom answered 8 months ago

In the first by-pass step of gluconeogenesis, the conversion of pyruvate to phosphoenolpyruvate, pyruvate is carboxylated...

In the first by-pass step of gluconeogenesis, the conversion of pyruvate to phosphoenolpyruvate, pyruvate is carboxylated by pyruvate carboxylase to oxaloacetate, which is subsequently decarboxylated by PEP carboxykinase to yield phosphoenolpyruvate. Explain using thermodynamic terms why this by-pass step is necessary. Why couldn't the glycolytic enzyme responsible for interconverting phosphoenolpyruvate and pyruvate also participate in the gluconeogenesis pathway?

In the absence of oxygen, pyruvate cannot be converted into acetyl-CoA. It is instead converted to ____...

In the absence of oxygen, pyruvate cannot be converted into acetyl-CoA. It is instead converted to ____ and must go to the Cori Cycle into glucose to generate energy. You would notice this during your exercise. lactic acid ketones glucose lactose

Pyruvate stands at a metabolic crossroad. Describe how pyruvate is converted into four different products.

Which molecule is reduced in the cytosol to a molecule that is then converted to pyruvate?

In gluconeogenesis, the pyruvate to phosphoenolpyruvate is one of the bypass steps that is different from...

In gluconeogenesis, the pyruvate to phosphoenolpyruvate is one of the bypass steps that is different from the reverse reaction in glycolysis due to the irreversible nature of pyruvate kinase. There are two pathways for this bypass reaction that differ in the location where the final PEP product is synthesized – either in the mitochondria or in the cytoplasm. Assume that your cell is undergoing gluconeogenesis using pyruvate derived from the deamination of serine by the enzyme serine dehydratase: L-serine →...

5.Consider the regulation of glycolysis, gluconeogenesis, pyruvate dehydrogenase, and the TCA cycle, how is the regulation...

5.Consider the regulation of glycolysis, gluconeogenesis, pyruvate dehydrogenase, and the TCA cycle, how is the regulation of these pathways linked to thermodynamics? How are they linked to one another?

Compare the ATP yield of three glucose molecules that enter glycolysis and are converted to pyruvate...

Compare the ATP yield of three glucose molecules that enter glycolysis and are converted to pyruvate with that of three glucose molecules that proceed through the pentose phosphate pathway such that their carbon skeletons (as two F6P and one GAP) reenter glycolysis and are metabolized to pyruvate. Indicate the steps where ATP was used or produced and the overall ATP totals.

Compare the ATP yield of three glucose molecules that enter glycolysis and are converted to pyruvate...

Compare the ATP yield of three glucose molecules that enter glycolysis and are converted to pyruvate with that of three glucose molecules that proceed through the pentose phosphate pathway such that their carbon skeletons (as two F6P and one GAP) reenter glycolysis and are metabolized to pyruvate. Indicate the steps where ATP was used or produced and the overall ATP totals.

NADH is required for the one-step reaction by which pyruvate is converted to; A. Oxaloacetate B....

NADH is required for the one-step reaction by which pyruvate is converted to; A. Oxaloacetate B. Acetyl CoA C. Phosphoenolpyruvate D. Lactate Bacterial DNA is not bound to histones unlike eukaryotic DNA T/F? All sphingolipids have in common which of the following? A. A glycerol backbone B. Ceramide C. Phosphorylcholine D. N-acetylneuraminic acid (NANA) E. A steroid ring structure to which spingosine is attached

Gluconeogenesis is generally the reverse of the glycolytic pathway, producing glucose from pyruvate. Some tissues cannot...

Gluconeogenesis is generally the reverse of the glycolytic pathway, producing glucose from pyruvate. Some tissues cannot survive without a source of glucose, and this is a way to produce glucose from other food molecules. (A) 7 reactions in glycolysis are used in the reverse direction in gluconeogenesis. How can this be?

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In gluconeogenesis, pyruvate is converted to PEP in two reactions. These reactions include an initial carboxylation...

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In the first by-pass step of gluconeogenesis, the conversion of pyruvate to phosphoenolpyruvate, pyruvate is carboxylated...

In the absence of oxygen, pyruvate cannot be converted into acetyl-CoA. It is instead converted to ____...

Pyruvate stands at a metabolic crossroad. Describe how pyruvate is converted into four different products.

Which molecule is reduced in the cytosol to a molecule that is then converted to pyruvate?

In gluconeogenesis, the pyruvate to phosphoenolpyruvate is one of the bypass steps that is different from...

5.Consider the regulation of glycolysis, gluconeogenesis, pyruvate dehydrogenase, and the TCA cycle, how is the regulation...

Compare the ATP yield of three glucose molecules that enter glycolysis and are converted to pyruvate...

Compare the ATP yield of three glucose molecules that enter glycolysis and are converted to pyruvate...

NADH is required for the one-step reaction by which pyruvate is converted to; A. Oxaloacetate B....

Gluconeogenesis is generally the reverse of the glycolytic pathway, producing glucose from pyruvate. Some tissues cannot...