• Four main classes of important large(ish) molecules

  1. Carbohydrates
  2. Lipids*
    • *Lipids are not macromolecules → Too small, do not form Polymers
  3. Proteins
  4. Nucleic Acids

Carbohydrates, proteins, and nucleic acids are MACROMOLECULES

• Cells make and break polymers in similar ways • Enzymes help out – very important • Enzymes – Increase the rate of a reaction without being consumed by the reaction (most are proteins)

• Dehydration reaction – 2 molecules covalently bonded to one another – One molecule of H2O is lost • Hydrolysis – Essentially the reverse of the dehydration reaction – It means to break, using water

• Ex: digestion – Enzymes attack polymers → speed up hydrolysis – Released monomers are absorbed into the bloodstream for distribution to all body cells – Cells can use dehydration reactions to assemble monomers into different polymers