Glucose is a simple carbohydrate comprised of oxygen, hydrogen and carbon with a molecular formula of C6H12O6. This compound is naturally present in the majority of food sources, such as fruits, vegetables and legumes, and circulates in your blood at a typical concentration of 65 to 110 mg/mL. As you digest your food, you render glucose molecules that supply energy to your body. The breakdown of glucose occurs through a process called glycolysis to yield pyruvate, which is the precursor to the citric acid cycle -- a part of the metabolic pathway to turn food into energy.
Step 1
Phosphorylate the glucose molecule, which is the process that adds a phosphate group to the glucose. The enzyme hexokinase facilitates the reaction by providing a magnesium atom to remove the negative ion supplied by ATP, or adenosine triphosphate, the molecule that supplies the energy for the reaction to take place. This phosphorylation yields the molecule glucose-6-phosphate.
Step 2
Convert glucose-6-phosphate to fructose-6-phosphate using the enzyme phosophglucose isomerase. The reaction between the glucose-6-phosphate molecule and the enzyme causes the carbon-oxygen bond on the six-membered ring to become a five-membered ring.
Step 3
Apply a second ATP molecule and the enzyme phosphofructokinase to the fructose-6-phosphate to yield fructose-1,6-bisphosphate. Here, the magnesium atom, which contains a positive charge, neutralizes the negative charge of the ATP.
Step 4
Utilize the aldolase enzyme to break down the fructose-1,6-bisphosphate molecule into two separate molecules of dihydroxyacetone phosphate and glyceraldehyde-3-phosphate.
Step 5
Oxidize the glyceraldehyde-3-phosphate enzyme using coenzyme nicotinamide adenine dinucleotide, or NAD. Phosphorylate the molecule by adding a free phosphate group to yield 1,3-bisphoglycerate. The structure of the initial molecule allows the NAD to pull a hydrogen atom off to make NADH.
Step 6
Convert both 1,3 bisphoglycerate molecules to 3-phosphoglycerate using the enzyme phosphoglycerate kinase, or PGK. This reaction causes the molecule to lose a phosphate group, which combines with adenosine diphosphate, ADP, to yield two adenosine triphosphate, or ATP.
Step 7
Rearrange the phosphate group position on the 3-phosphoglycerate molecule by using the catalysis phosphoglycerate mutase, which transfers the phosphate group to a 2-phosphoglycerate position.
Step 8
Use the enzyme enolase to catalyze the 2-phosphoglycerate molecule to phosphoenolpyruavate, or PEP. Through a dehydration reaction -- the removal of a water molecule -- the enzyme removes water to create phosphoenolpyruvate.
Step 9
Reduce phosphoenolypyruvate into pyruvate by transferring a phosphate group. The ADP pulls the phosphate group from the phosphoenolpyruvate creating a pyruvate molecule and an ATP molecule. Since there are two initial molecules, this will occur twice yielding two pyruvate molecules and two ATP molecules.
