- Monosaccharide contain 2-7 atoms
- Most common monosaccharide in food contain 6 carbon atoms (called hexoses) and therefore their formula is C6H1206.
- Found in large amounts in grapes and smaller amounts in carrots and peas.
Glucose syrup which is used in commercial manufacture is not pure glucose, but a mixture of other carbohydrates, glucose and water.
Formula= C x H20y
Carboyhrates can be split up into:
Sugars- Monosaccharides such as glucose and fructose
- Disaccharides such as maltose, sucrose, lactose.
Non sugars- Simple polysaccharides such as starch, cellulose, glycogen
- Complex polysaccharides such as pectin and gums.
Two forms of glucose:
Alpha- The hydroxyl group (OH) is at the bottom of the structure
Beta- The hydroxyl group (OH) is at the top.
Glucose is a reducing sugar, this means it has the ability to break down.
Fructose is one and a half times sweter than glucose
- An equal mixture of fructose and sucrose is called an invert sugar which is found in honey.
- The structure of fructose changes depending on if it is found on its own or whether it is joined with other sugars.
This doesn't occur in food but is formed when lactose is broken down during digestion
Formed when two monosaccharides join together during a condensation reaction (when water is eliminated)
- Sugar found only in milk
- Cows milk has 4-5%
- Human milk 6-8%
- This reducing sugar is formed by joining together glucose and galactose
- Formed when two glucose units join together
- When the two units join, water is eliminated and the remaining 02 atom forms a bridge between two glucoses.
- This bridge is called a glycosidic link
- Maltose is a reducing sugar
- During digestion, starch is broken down by the enzyme amylase (this enzyme is present in out saliva).
- Formed by 1 glucose unit joined with 1 fructose unit
- Ordinary suagr is almost pure sucrose
Glucose + Glucose= Maltose
Glucose + Fructose= Sucrose
Glucsoe + Galactose= Lactose
Chemical breakdown of a molecule when it combines with water and produces two smallwe molecules
C12 + H22 + 0H + H20 = 2C6 H12 06 ( Hydrolysis of different disaccharides)
Maltose + Water = Glucose + Glucose
Sucrose + Water = Glucose + Fructose
Lactose + Water = Glucose + Galactose