Glucose Chemical Formula

Glucose, a monosaccharide or simple sugar, has the chemical formula C6𝐻12𝑂6. In this article, we will explore the glucose chemical formula, its structure, properties, and various isomers in detail.

What is Glucose Chemical Formula?

Glucose, a fundamental carbohydrate, has the molecular formula 𝐶6𝐻12𝑂6, indicating its composition of six carbon (C) atoms, twelve hydrogen (H) atoms, and six oxygen (O) atoms arranged in a hexagonal ring. As a monosaccharide, or simple sugar, glucose is the primary energy source for living organisms through cellular respiration. It plays a crucial role in metabolism and energy production, making it essential in biological systems. Furthermore, glucose molecules can link together through glycosidic bonds to form complex carbohydrates like starch and cellulose, which are vital for plant and human nutrition.

How can we get Glucose Naturally?

Glucose is produced by plants during photosynthesis, utilizing water and carbon dioxide in the presence of sunlight. This glucose is then used to form cellulose in plant cell walls. Glucose, the most abundant carbohydrate globally, has the chemical formula 𝐶6𝐻12𝑂6 . It is a simple sugar, known as a monosaccharide, and is chemically referred to as D-glucose.

6CO₂ + 12H₂O ⇒ C₆H₁₂O₆ + 6O₂ + 6H₂O

Glucose Formula Structure

Glucose, a simple sugar belonging to the carbohydrates group, consists of six carbon atoms. It exists in two forms:

• Acyclic (open chain) form
• Cyclic (ring) form

In its structure, each carbon atom forms four covalent bonds, each oxygen atom forms two covalent bonds, and each hydrogen atom forms one covalent bond.

Open Chain: In its open-chain form, glucose has a straight, unbranched backbone containing six carbon atoms. This is confirmed by its reduction with concentrated hydrogen iodide and red phosphorus.

Unbranched Six-Carbon Chain: Glucose features an unbranched chain of six carbon atoms, indicated by the reduction reaction mentioned above.

Five Hydroxyl (OH) Groups: Glucose reacts with acetic anhydride to form pentacetate derivatives, demonstrating the presence of five hydroxyl groups. Given glucose’s stability, no two OH groups are attached to the same carbon atom, meaning the five OH groups are distributed across different carbons. When glucose interacts with hydroxylamine, it forms an oxime, indicating a carbonyl group is present.

Terminal CHO Function: Mild oxidation of glucose with bromine water converts it to gluconic acid, and further reduction with hydrogen iodide yields hexanoic acid. This indicates the presence of a terminal aldehyde (CHO) group.

To form an open-chain structure of glucose, the five OH groups are placed on five different carbons of the straight six-carbon chain with a terminal CHO group. Adding hydrogen atoms to these carbon atoms satisfies their valencies, resulting in the complete open-chain structure of glucose.

Preparation Of Glucose (C6H12O6)

Sucrose (cane sugar) and starch are the two primary sources of glucose.

Preparation from Sucrose (Cane Sugar)

Sucrose, a disaccharide with the formula C12H22O11, can be broken down into glucose and fructose in equal amounts. This is achieved by boiling an aqueous solution of sucrose with dilute hydrochloric acid (HCl) or dilute sulfuric acid (H2SO4).

C₁₂H₂₂O₁₁ + H₂O  →  C₆H₁₂O₆ + C₆H₁₂O₆

Sucrose                      Glucose       Fructose

Preparation from Starch

Starch, a polysaccharide, can be converted into glucose by boiling it with dilute sulfuric acid (H2SO4) at a temperature of 393 K and under a pressure of 2 to 3 atmospheres.

( C₆H₁₂O₅)_n   +   n H₂O   →    nC₆H₁₂O₆  

Starch                                   Glucose

Photosynthesis

Plants produce food glucose in the presence of carbon dioxide, water, and sunlight. It is the main source of energy for plants and oxygen in the environment. The chemical reactions involved in photosynthesis are:

6CO₂+6H₂O→C₆H₁₂O₆+6O₂

Glycogenolysis

In animals, glycogen, the major carbohydrate stored in animal liver and muscle cells, is broken down into simple glucose molecules to provide immediate energy and maintain blood sugar levels during fasting. 

Physical Properties of Glucose

• Glucose can exist in both solid and liquid states.
• It has a sweet taste.
• It is soluble in water.
• It appears colorless and clear.
• The boiling point of glucose is 294.8°F (146°C).
• The melting point of glucose is approximately 527.1 °C, with a margin of error of ±50 °C at 760 mmHg.

Chemical Properties of Glucose

• The chemical formula for glucose is C₆H₁₂O₆.
• The IUPAC name for glucose is D-glucose.
• The density of glucose is 1.54 g/cm³.
• The molecular weight of glucose is 186.16 g/mol.
• Glucose is referred to as a simple sugar because it is a monosaccharide.
• It is odorless.

Application of Glucose

• It is utilized in the treatment of hypoglycemia (low blood sugar levels).
• It provides carbohydrate calories.
• It serves as a precursor for the synthesis of various substances.
• Glucose is used as the first-line treatment for “hyperkalemia,” which causes elevated potassium levels in the body.
• It helps store carbon and carbohydrates in both solid and liquid forms.
• It can be directly injected into the bloodstream for rapid recovery.
• It is essential for producing energy in living organisms.