Asked by: Adorinda Tihy
healthy living nutrition

How is pyruvate converted to Oxaloacetate?

Last Updated: 24th April, 2020

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Pyruvate is first converted by pyruvate carboxylase to oxaloacetate (OAA) in the mitochondrion requiring hydrolysis of one molecule of ATP. However, during starvation when cytosolic NADH concentration is low and mitochrondrial NADH levels are high oxaloacetate can be used as a shuttle of reducing equivalents.

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Similarly one may ask, which coenzyme is required for the conversion of pyruvate to oxaloacetate?

acetyl Coenzyme A

what makes Oxaloacetate? A pyruvate molecule is carboxylated by a pyruvate carboxylase enzyme, activated by a molecule each of ATP and water. This reaction results in the formation of oxaloacetate. NADH reduces oxaloacetate to malate. This transformation is needed to transport the molecule out of the mitochondria.

Herein, how is Oxaloacetate used in gluconeogenesis?

Gluconeogenesis begins in the mitochondria with the formation of oxaloacetate by the carboxylation of pyruvate. This reaction also requires one molecule of ATP, and is catalyzed by pyruvate carboxylase. Oxaloacetate is decarboxylated and then phosphorylated to form phosphoenolpyruvate using the enzyme PEPCK.

Which amino acids are converted to Oxaloacetate?

Aspartate and asparagine are converted into oxaloacetate, a citric acid cycle intermediate. Aspartate, a four-carbon amino acid, is directly transaminated to oxaloacetate.

Related Question Answers

Dirk Mikheev

Professional

What is the process of gluconeogenesis?

Gluconeogenesis is a pathway used by the body to create glucose from other molecules and an important pathway that allows the body to store needed energy for the brain in the form of glucose. It is essentially glycolysis, which is the process of converting glucose into energy, in reverse.

Jamina Maitena

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How does pyruvate enter the mitochondrion?

The transport of pyruvate into the mitochondria is via the transport protein pyruvate translocase. Pyruvate translocase transports pyruvate in a symport fashion with a proton, and hence is active, consuming energy. Upon entry to the mitochondria, the pyruvate is decarboxylated, producing acetyl-CoA.

Fe Scheibli

Explainer

Where does the conversion of pyruvate to OAA occur?

During gluconeogenesis, pyruvate carboxylase is involved in the synthesis of phosphoenolpyruvate (PEP) from pyruvate. Pyruvate is first converted by pyruvate carboxylase to oxaloacetate (OAA) in the mitochondrion requiring hydrolysis of one molecule of ATP.

Zayd Christel

Explainer

Can Oxaloacetate cross mitochondrial membrane?

Oxaloacetate (OAA) cannot cross the inner mitochondrial membrane. The problem is that the inner mitochondrial membrane is not permeable to NADH , so a shuttle system is required for the transport of the reducing equivalents through the mitochondrial membrane.

Alease Offermans

Explainer

Why does acetyl CoA activate pyruvate carboxylase?

More specifically pyruvate carboxylase is activated by acetyl-CoA. Because acetyl-CoA is an important metabolite in the TCA cycle which produces a lot of energy, when concentrations of acetyl-CoA are high organisms use pyruvate carboxylase to channel pyruvate away from the TCA cycle.

Lavera Dauphin

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Do humans have pyruvate decarboxylase?

It is made up of about 96 subunits organized into three functional enzymes in humans: 20-30 copies of pyruvate dehydrogenase E1 component, 60 copies of pyruvate dehydrogenase E2 component, and 6 copies of dihydrolipoyl dehydrogenase (E3).

Meiyu Baetzel

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Is pyruvate dehydrogenase reversible?

Pyruvate dehydrogenase (PDH) catalyzes an irreversible and no return metabolic step because its substrate pyruvate is gluconeogenic or anaplerotic, whereas its product acetyl-CoA is not [62–65].

Albita Malki

Pundit

Which amino acids Cannot be converted to glucose?

Fatty acids and ketogenic amino acids cannot be used to synthesize glucose. The transition reaction is a one-way reaction, meaning that acetyl-CoA cannot be converted back to pyruvate. As a result, fatty acids can't be used to synthesize glucose, because beta-oxidation produces acetyl-CoA.

Olaiz

Pundit

What hormone stimulates gluconeogenesis?

Gluconeogenesis occurs in the liver and kidneys. Gluconeogenesis supplies the needs for plasma glucose between meals. Gluconeogenesis is stimulated by the diabetogenic hormones (glucagon, growth hormone, epinephrine, and cortisol).

Hadjira Nesbitt

Teacher

What amino acids can be converted to glucose?

A glucogenic amino acid is an amino acid that can be converted into glucose through gluconeogenesis.

In humans, the glucogenic amino acids are:
  • Alanine.
  • Arginine.
  • Asparagine.
  • Aspartic acid.
  • Cysteine.
  • Glutamic acid.
  • Glutamine.
  • Glycine.

Clark Cordoves

Teacher

Erin Janariz

Teacher

What is the end product of gluconeogenesis?

Glucose-6-phosphate is synthesized directly from glucose or as the end product of gluconeogenesis.

Issouf Pedros

Teacher

Is glycolysis anabolic or catabolic?

Answer and Explanation: Glycolysis is considered a catabolic reaction. Catabolism refers to the breakdown of large molecules into smaller molecules, while anabolism is the Glycolysis is considered a catabolic reaction.

Osbaldo Emke

Reviewer

What are the three stages of glycolysis?

The glycolytic pathway can be divided into three stages: (1) glucose is trapped and destabilized; (2) two interconvertible three-carbon molecules are generated by cleavage of six-carbon fructose; and (3) ATP is generated.

Jamile Eisentrager

Reviewer

Where is glycogen stored?

Glycogen functions as one of two forms of long-term energy reserves, with the other form being triglyceride stores in adipose tissue (i.e., body fat). In humans, glycogen is made and stored primarily in the cells of the liver and skeletal muscle.

Nelsa Essink

Reviewer

What foods contain Oxaloacetate?

Oxaloacetate is in every food you eat. It's in chicken, it's in peas, it's in potatoes, it's in apples, it's in spinach." And they said, "Well yes, but nobody has been selling food specifically for it's oxaloacetate content.

Mack Seubelt

Reviewer

What happens if Oxaloacetate is not present?

If insufficient oxaloacetate is present, which generally occurs when the glucose is not present in the considerable amounts, then oxaloacetate is synthesized with the help of pyruvate, which is a product of glycolysis and is formed by the synthesis of fatty acids, other than from acetyl CoA.