IB Biology B1.1 Notes

Now that you understand how molecules are formed and whether they are polar or non-polar, you need to understand that organic molecules are categorized into two types:

1. Monomers - these are the simplest units of organic molecule types. Examples include:
   1. Monosaccharides - carbohydrate monomers.
   2. Amino acids - protein monomers.
   3. Nucleotides - DNA and RNA monomers.
2. Macromolecules - these are monomers linked together to form larger molecular structures. Two monomers linked together are called a dimer, and three or more monomers linked together are called a polymer. Examples include:
   1. Polysaccharides - carbohydrate macromolecules
   2. Polypeptides - protein macromolecules
   3. Nucleic acids - nucleic acid macromolecules

Monomers and macromolecules are formed by two types of reactions:

1. Condensation reactions - these link monomers together to form a macromolecule and water.
2. Hydrolysis reactions - these use water to split macromolecules into monomers.