What is the Difference Between Glucose 6 Phosphate and Fructose 6 Phosphate

The key difference between glucose 6 phosphate and fructose 6 phosphate is that glucose 6 phosphate has a phosphate group attached to the 6^th carbon atom of the glucose molecule, whereas fructose 6 phosphate has a phosphate group attached to the 6^th carbon of the fructose molecule.

Glucose 6 phosphate and fructose 6 phosphate are important sugar compounds that have undergone phosphorylation to attach phosphate groups into these sugar molecules.

CONTENTS

1. Overview and Key Difference
2. What is Glucose 6 Phosphate
3. What is Fructose 6 Phosphate
4. Glucose 6 Phosphate vs Fructose 6 Phosphate in Tabular Form
5. Summary – Glucose 6 Phosphate vs Fructose 6 Phosphate

What is Glucose 6 Phosphate?

Glucose 6 phosphate is a glucose sugar that is phosphorylated at the hydroxy group on carbon 6. This is a dianion, and it is common in cells because the majority of the glucose entering a cell becomes phosphorylated at 6^th carbon atom. Due to its prominent position in cellular chemistry, this compound has many possible fates inside a cell. It also tends to lie at the start of two major metabolic pathways, including glycolysis and the pentose phosphate pathway. Additionally, these two metabolic pathways also include the conversion of glucose 6 phosphate into glycogen or starch for storage. The storage is done in the liver and muscles as glycogen.

The chemical formula of glucose 6 phosphate is C₆H₁₃O₉P. Its molar mass is 260.136 g/mol. Inside a cell, glucose 6 phosphate can be produced via phosphorylation of glucose on the sixth carbon, which is catalyzed by the enzyme hexokinase in most cells. In higher animals, glucokinase is used in certain cells, such as liver cells. In this reaction, one equivalent of ATP is consumed. This immediate phosphorylation occurs in order to prevent diffusion out of the cells. Moreover, this process adds a charged phosphate group, making it easy to cross through the cell membrane.

When cells need energy for carbon skeleton synthesis, cells target glucose 6 phosphate for glycolysis. First, this compound is isomerized to fructose 6 phosphate via phosphor-glucose isomerase. It uses magnesium as a cofactor.

What is Fructose 6 Phosphate?

Fructose 6 phosphate is a glucose sugar having the chemical formula C₆H₁₃O₉P. Its molar mass is 260.14 g/mol. It is a derivative of fructose. Fructose is phosphorylated at the 6^th hydroxy group. We can call it fructophosphate. It has a beta-D form that is very common in cells. Moreover, most of the glucose is converted into fructose 6 phosphate upon entering a cell. Predominantly, fructose converts into fructose 1 phosphate in the presence of fructokinase.

In the process of glycolysis, fructose 6 phosphate lies within the glycolysis metabolic pathway, and it is produced by the isomerization of glucose 6 phosphate. Moreover, it can be further phosphorylated into fructose-1,6-bisphosphate.

What is the Difference Between Glucose 6 Phosphate and Fructose 6 Phosphate?

The key difference between glucose 6 phosphate and fructose 6 phosphate is that glucose 6 phosphate has a phosphate group attached to the 6^th carbon atom of the glucose molecule, whereas fructose 6 phosphate has a phosphate group attached to the 6^th carbon of the fructose molecule. Furthermore, glucokinase or hexokinase IV is the enzyme involved in the production of glucose 6 phosphate while phosphofructokinase is the enzyme involved in the production of fructose 6 phosphate.

Below is a summary of the difference between glucose 6 phosphate and fructose 6 phosphate in tabular form for side-by-side comparison.

Summary – Glucose 6 Phosphate vs Fructose 6 Phosphate

Glucose 6 phosphate and fructose 6 phosphate are two glucose sugar having the chemical formula C₆H₁₃O₉P. The key difference between glucose 6 phosphate and fructose 6 phosphate is that glucose 6 phosphate has a phosphate group attached to the 6^th carbon atom of the glucose molecule, whereas fructose 6 phosphate has a phosphate group attached to the 6^th carbon of the fructose molecule.

Reference:

1. “Fructose 6-Phosphate.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Glucose-6-phosphate-skeletal” (Public Domain) via Commons Wikimedia
2. “Beta-D-fructose-6-phosphate wpmp” By Richard Wheeler (Zephyris) – en:Image:Beta-D-fructose-6-phosphate wpmp.png (Public Domain) via Commons Wikimedia