Building Biological Molecules (College Board AP® Biology): Study Guide

Building biological molecules

• The tissues of living organisms contain many macromolecules, e.g.:

  • cell membranes contain proteins

  • DNA is a nucleic acid

  • cells use carbohydrates as storage compounds

  • structural carbohydrates, such as cellulose, are needed for building cells

• Organisms gain the materials needed to build macromolecules by exchanging matter with their environment; this exchange involves processes such as eating, breathing and excreting

  • Continuous exchange of materials allows organisms to grow, reproduce and maintain their organization

• Examples of atoms that are exchanged with the environment include:

  • carbon, used to build:

    • carbohydrates and lipids

    • proteins

    • nucleic acids

  • nitrogen, used to build:

    • proteins

    • nucleic acids

  • phosphorus, used to build:

    • nucleic acids

    • some lipids