Why Is Glucose a Molecule?

Glucose, or blood sugar, has the chemical formula C6H1206. It is a carbohydrate, important in human metabolism. No single element can be used by the body to create energy; glucose combines elements into a compound that the body can produce, then burn as fuel.

Molecules Versus Atoms

Molecules are composed of atoms (or elements). Some substances, like gold, silver and oxygen, are composed of one element, but most are composed of several elements.

Elements Versus Compounds

Every atom is an element; two or more atoms in a bond are a compound. Compounds are most commonly composed of two or more elements.

Elements in Glucose

Glucose contains carbon, which exists by itself as coal, diamonds and other substances, plus hydrogen and oxygen, which both exist as gases. The three together form organic compounds, including glucose.

Functional Groups

Glucose contains some functional groups, including the hydroxyl group (-OH) and the aldehyde group (-O-CH). These are typical of sugars, and allow them to be metabolized for energy. Functional groups do not exist alone, but act like atoms, in that each group has individual properties.

Structure

Glucose in its dry form exists as a chain of six atoms. In a solution (including blood), it forms rings, something its functional groups allow.

References

• "Advanced Organic Chemistry"; Cary and Sundberg; 2007
• "General Chemistry"; Linus Pauling; 1988