The body uses glucose to make energy. Glucose oxidation rate is the rate at which glucose molecules convert to carbon dioxide. This rate is different for different organisms and conditions.
Glucose is a six-carbon sugar molecule cells use to create energy. When glucose is oxidised, it is broken down or metabolised. First, the six-carbon molecule becomes two three-carbon molecules, and then each of these three-carbon molecules is further oxidised to become carbon dioxide, a single-carbon molecule.
Oxidation rate is a measure of how fast an organism can break down the six-carbon glucose molecule into carbon dioxide molecules. Genetics and diet both influence oxidation rate.
Measuring Glucose Oxidation
Carbon-14 is a radioactive isotope that can be used to measure the rate of glucose oxidation in patients' tissues. Tissue samples are first labelled with glucose-containing radioactive carbon-14 molecules. Then rate of formation of radioactive carbon-14 dioxide over time yields a measurement of the rate of glucose oxidation.
Differences in Oxidation Rates
Various disease states can influence oxidation rates. For example, comparing gingival tissue from non-diabetic and diabetic patients revealed that the glucose oxidation rate for the non-diabetic tissue samples was faster than the rate from diabetic patients.
Rate Limiting Steps
Oxidation rate is influenced by both the levels of enzymes involved in oxidation and by the cell's specific energy needs. Cells that do not have an immediate need for energy may store glucose, rather than metabolise it into carbon dioxide.
- Pub Med: Cell size and glucose oxidation rate in adipose tissue from non-diabetic and diabetic obese human subjects
- Science Direct: The oxygen utilisation and glucose oxidation rate of gingival tissue from non-diabetic and diabetic patients
- Dr. Kaslow: Metabolism of Carbohydrates
- Journal of Applied Physiology: Reduced oxidation rates of ingested glucose during prolonged exercise with low endogenous CHO availability
- Medical Biochemistry Page: Glycolysis