oxaloacetate

(noun)

a four carbon molecule that receives an acetyl group from acetyl CoA to form citrate, which enters the citric acid cycle

Related Terms

Examples of oxaloacetate in the following topics:

  • The Reverse TCA Cycle

    • ATP citrate lyase is the enzyme responsible for cleaving citrate into oxaloacetate and acetyl CoA.
    • 1) oxaloacetate is converted to malate (NADH/H+ is utilized and NAD+ is produced)
    • 8) ATP citrate lyase is then used to convert citrate to oxaloacetate and acetyl CoA (ATP is hydrolyzed to ADP and Pi).

  • Acetyl CoA to CO2

    • In the presence of oxygen, acetyl CoA delivers its acetyl group to a four-carbon molecule, oxaloacetate, to form citrate, a six-carbon molecule with three carboxyl groups.
    • In addition to the citric acid cycle, named for the first intermediate formed, citric acid, or citrate, when acetate joins to the oxaloacetate, the cycle is also known by two other names.

  • Pyruvic Acid and Metabolism

    • Pyruvate is also converted to oxaloacetate by an anaplerotic reaction, which replenishes Krebs cycle intermediates; also, oxaloacetate is used for gluconeogenesis.

  • Connecting Lipids to Glucose Metabolism

    • The acetyl groups are picked up by CoA to form acetyl CoA that proceeds into the citric acid cycle as it combines with oxaloacetate.

  • Citric Acid Cycle

    • The first step is a condensation step, combining the two-carbon acetyl group (from acetyl CoA) with a four-carbon oxaloacetate molecule to form a six-carbon molecule of citrate.
    • The last step in the citric acid cycle regenerates oxaloacetate by oxidizing malate.
    • In the citric acid cycle, the acetyl group from acetyl CoA is attached to a four-carbon oxaloacetate molecule to form a six-carbon citrate molecule.

  • Citric Acid and Other Organic Compounds

    • It is produced from acetyl coenzyme A and oxaloacetate in the presence of the enzyme citrate synthase.

  • Polysaccharide Biosynthesis

    • PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of one guanosine triphosphate molecule.

  • Connecting Proteins to Glucose Metabolism

    • For example, deaminated asparagine and aspartate are converted into oxaloacetate and enter glucose catabolism in the citric acid cycle.

  • Breakdown of Pyruvate

    • Acetyl CoA is a molecule that is further converted to oxaloacetate, which enters the citric acid cycle (Krebs cycle).

  • CAM and C4 Photosynthesis

    • CAM plants store the CO2 mostly in the form of malic acid via carboxylation of phosphoenolpyruvate to oxaloacetate, which is then reduced to malate.