Macromolecules: Proteins, Polysaccharides, Nucleic Acids, Lipids


▶️ Watch on 3Speak

In this video I go over the properties and structures of the 4 main types of macromolecules (or very large molecules) that are found in all living organisms: proteins, polysaccharides, nucleic acids, and lipids. The first 3 (proteins, polysaccharides, nucleic acids) are formed from smaller repeating units called monomers. On the other hand, lipids are not defined by any chemical structure and represent a broad group of organic compounds such as fats, phospholipids, and steroids. More terms and definitions are listed in the timestamps below.


  • Macromolecules or very large molecules: 0:00
  • Table of 4 major macromolecules: proteins, nucleic acids, polysaccharides, lipids: 0:56
  • Specialized roles of macromolecules in cells: 3:44
  • Lipids are only class of macromolecules not made up of polymers (not composed of smaller repeating monomers): 4:08
  • Phospholipids or phosphatides are lipids with a hydrophilic head containing a phosphate and 2 hydrophobic tails derived from fatty acids: 4:21
  • Phospholipid forming cell membrane bilayer: 4:56
  • Lumen is inside space of a tubular structure: 5:30
  • Steroid is a lipid with four rings and is biologically active: 5:37
  • Cholestane steroid structure: 6:00
  • Membrane fluidity is the viscosity of the lipid bilayer of a cell membrane: 6:28
  • 3 main structures of phospholipids: liposome, micelle, bilayer sheet: 7:09
  • Proteins are most diverse macromolecules. Nucleic acids handle hereditary information: 7:51
  • Antibody (Ab) or immunoglobulin (Ig) are Y-shaped proteins that attack foreign objects: 8:11
  • Antigen is unique molecule of the pathogen which the antibody recognizes: 8:35
  • Antibody-antigen binding site via lock and key theory: 9:16
  • Primary, secondary, tertiary, quaternary structures of a hemoglobin protein: 9:56
  • Hemoglobin (Hb or Hgb) contains iron and transports oxygen in the red blood cells: 12:32
  • Red blood cells (RBCs) or red cells or erythrocytes are main means of delivering oxygen to the body tissues: 12:42
  • Biomolecular structure is the folded, 3D shape formed by a molecule of protein, DNA, or RNA: 13:29
  • Protein complex is a group of 2 or more polypeptide chains and are form of quaternary structure: 14:02
  • 4 main scales of molecular structure: primary, secondary, tertiary, and quaternary: 14:37
  • Scaffold or support for the biomolecular structure arises from the hydrogen bonds at the secondary level: 14:47
  • Diagram of 4 levels of structure for proteins and nucleic acids: 15:14
  • Histones are proteins that act as spools for DNA to wrap around it forming structural units called nucleosomes: 17:10

Full video below:

  • HIVE video notes:
  • Video sections playlist:
  • #MESScience playlist: .

  • Become a MES Super Fan!

    DONATE! ʕ •ᴥ•ʔ


    MES Links:

    MES Truth:
    Official Website:

    Email me: [email protected]

    Free Calculators:

    BMI Calculator:
    Grade Calculator:
    Mortgage Calculator:
    Percentage Calculator:

    Free Online Tools:

    iPhone and Android Apps:

    ▶️ 3Speak