1. Biological Molecules

2. Macromolecule: Monomer: Polymer:
very large organic molecules containing many different elements
e.g. lipids = fatty acids + glycerol
Monomer:
small building blocks which are identical or very similar
e.g. nucleotides, glucose, amino acids
Polymer:
monomers joined together
e.g. DNA, starch, proteins

3. Organic Macromolecules
The main organic macromolecules to be studied are carbohydrates, proteins, lipids and nucleic acids.
They all contain the elements carbon, hydrogen and oxygen.

4. Polymers form by condensation reactions
Individual monomers join by condensation reactions to form polymers, releasing water.
The hydroxide groups (OH) from two monomers react.
Hydrogen (H) from one and hydroxide (OH) from the other are released as water.
The monomers then join by the remaining oxygen atom (O)

5. HO OH HO OH H2O HO O OH HYDROLYSIS CONDENSATION Broken down with the
monomer HO OH
monomer
H2O
HYDROLYSIS
Broken down with the
addition of a
water molecule
CONDENSATION
linked with the
removal of a
water molecule HO O OH

6. Condensation reactions occur in the formation of carbohydrates, lipids and proteins, where the OH group may be part of other larger groups.