What Are the Properties of Glucose?

Glucose is a carbohydrate and the most important simple sugar for metabolism. It is the primary source of fuel used by your body. One mole of glucose yields about 2870 kJ of energy.

Facts

• Glucose is a monosaccharide (simple carbohydrate). Glucose exists as D-(+)-glucose and L-(-)-glucose. The D-(+)-glucose form is used as fuel by your body and is also called dextrose, however L-(-)-glucose cannot be used by your body as a source of energy.

Identification

• Both forms of glucose have a molecular formula of C6H12O6 and are sweet-tasting, white, crystalline powders with a melting point of 153 to 156°C (307--312°F). Glucose exists mostly in the cyclic chair form, but it can exist in chain form.

General Properties

• Molecular mass = 180.16 g/mol
  Density = 1.54 g/cm3
  SMILES: C(C1C(C(C(C(O1)O)O)O)O)O

Properties D-(+)-glucose

• Optical rotation = 49° to 55° (10% solution)
  Solubility in water = 133 mg/mL
  WISWESSER LINE NOTATION : T6OTJ BQ CQ DQ EQ F1Q -D,GLU
  LD50 (oral, rat) = 25800 mg/kg
  Log KOW = - 3.24
  pKa = 12.92 @ 0°C (32°F)
  pH = 5.9 (0.5M solution)

Properties L-(-)-glucose

• Optical rotation = -53° to -51° (10% solution)
  Solubility in water = 50 mg/mL

Reactivity and Stability

• Glucose reacts violently with sodium peroxide and potassium nitrate. It is stable below 50°C (122°F).

Importance in Metabolism

• Your body converts many other monosaccharides, such as fructose and galactose, into glucose. Your body can also break down disaccharides (such as lactose and sucrose) and polysaccharides (such as starch) into glucose. Some fats and proteins can be converted into glucose as well. Your body controls the amount of glucose in your blood using hormones. One mole of glucose yields about 2870 kJ of energy. Eating large amounts of glucose can cause excessive motility of the stomach or intestines and diarrhea.