1. Biological
Molecules

2. Based on a small number of
chemical elements – mainly carbon
Are very large
Made up of monomers combined to produce polymers
Made by the process known as condensation

3. Carbohydrates Compounds of carbon, hydrogen and oxygen
They have the common formula Cx(H2O)y where x and y are variable numbers
Three main types Monosaccharides
Disaccharides
Polysaccharides

4. Monosaccharides The simple sugars
Have the general formula (CH2O)n – n can be any number from 3 – 7
Grouped according to value of n
N=3 triose
N=4 tetrose
N=5 pentose
N=6 hexose
N=7 heptose

5. Glucose A hexose sugar with formula C6H12O6
Is the main energy source for most living cells
Exhibits ISOMERISM - when molecules have the same chemical formula but a different structural formula
Two common isomers are a-glucose and b-glucose

7. O HO H OH
a Glucose
OH down O HO OH H
b Glucose
OH up

8. Fructose A hexose sugar with formula C6H12O6
Is the sugar found in most fruits

9. Disaccharides Formed when two monosaccharides join together
This reaction releases water and is therefore called a CONDENSATION REACTION.
The link between the 2 monosaccharide molecules is called a GLYCOSIDIC BOND

10. O HO H OH O HO H OH
H2O HO O H OH
Glycosidic bond

11. 1-4 glycosidic bonds

13. Disaccharides can be formed by joining together:
2 similar monosacs eg maltose – 2 glucose
2 different monosacs eg sucrose –glucose fructose
Disaccharides can be broken back down into monosaccharides by the process known as HYDROLYSIS – adding a molecule of water