Preparation of Glucose

• From Sucrose (Cane sugar): When sucrose is boiled in an alcoholic solution with dilute HCl or H₂SO₄ equal amounts of glucose and fructose are obtained.

C₆H₂₂O₁₁(sucrose) + H₂O → C₆H₁₂O₆(glucose) + C₆H₁₂O₆(fructose)

• From Starch: Glucose is produced commercially by the hydrolysis of starch by boiling it with dilute H₂SO₄ at 393 K under the pressure of 2–3 atm.

(C₆H₁₀O₅)(starch) + nH₂O → C₆H₁₂O₆(glucose)

In this process, an aqueous solution of starch obtained from corn is acidified with dilute H₂SO₄ then it is heated in an autoclave under 2-3 atm pressure steam. When hydrolysis is complete, the liquid is neutralized with sodium carbonate to a pH of 4–5. The resulting solution glucose Xe is concentrated under reduced pressure to obtain crystals of glucose.

Fructose

Fructose is found in fruits and is called fruit sugar. It is also present in honey and sweet fruits along with glucose. In the combined state, it is also present in disaccharides (sucrose) and polysaccharides (insulin).

It is obtained by hydrolysis of cane sugar with dilute H₂SO₄ with glucose.

C₁₂H₂₂O₁₁ + H2O → C₆H₁₂O₆(D- glucose) + C₆H₁₂O₆(D- fructose)

This solution containing equal molecules of D-glucose and D-fructose is called invert sugar.

Check:

• Polysaccharides
• Disaccharides

The branch of chemistry that deals with the molecules involved in living things is called biochemistry. Carbohydrates, proteins, vitamins, and nucleic acids are some of the major components of our body. These are collectively called biomolecules.

A biomolecule is sometimes associated as a biological molecule, a term that refers to molecules found in living objects that are important for one or additional biological processes, analogous to cell division, morphogenesis, or development. Large macromolecules (or polyanions) similar to proteins, carbohydrates, lipids, and nucleic acids, as well as primary metabolites, secondary metabolites, and smaller moieties, similar to natural products, are all examples of biomolecules. Natural material is the more broad term for this type of material. Biomolecules are essential factors of living organisms. While endogenous biomolecules are made within the organism, organisms usually require external biomolecules, such as specific nutrients, to be present.

Carbohydrates are optically active polyhydroxy aldehydes or polyhydroxy ketones or substances that upon hydrolyzed would produce these types of compounds.