Table 2.

The reactions, enzymes, transporters, and overall equation of gluconeogenesis

ReactionsEnzymes
1Embedded ImageMitochondrial pyruvate transporter
2Embedded ImageMitochondrial pyruvate carboxylase
3Embedded ImageMitochondrial malate dehydrogenase
4Embedded ImageMitochondrial malate transporter
5Embedded ImageMalate dehydrogenase
6Embedded ImagePEP carboxykinase
7Embedded ImageEnolase
8Embedded ImagePhosphoglycerate mutase
9Embedded ImagePhosphoglycerate kinase
10Embedded Image3-Phoglyceraldehyde dehydrogenase
11Embedded ImageTriose phosphate mutase
12Embedded ImageAldolase
13Embedded ImageFructose-1,6-bisphosphatase
14Embedded ImagePhosphoglucoisomerase
15Embedded ImageGlucose-6-phosphatase
Overall equation: Embedded Image
  • Two (3C)molecules are needed to synthesize one (6C)glucose molecule. Therefore, reactions 1–10 are multiplied by 2. The majority of the single reactions are catalyzed by cytosolic enzyme proteins. However, steps 1–4 require the intervention of 2 mitochondrial transporters and 2 mitochondrial enzyme proteins. The overall equation of gluconeogenesis starting from 2 cytosolic PEP molecules (reactions 7–15) is Embedded Image.