c. Biological Molecules

• Biological molecules:

  • found in living organisms
  • produced by cells
• Nutrients = molecules that are needed for growth
• Biological molecules (regarding human nutrition) are:

  • carbohydrates
  • proteins
  • lipids
• Carbohydrates are made of:

  • carbon
  • hydrogen
  • oxygen
• Proteins are made of:

  • carbon
  • hydrogen
  • oxygen
  • nitrogen
• Lipids are made out of:

  • carbon
  • hydrogen
  • oxygen
• CARBS COME IN DIFFERENT SIZES

  Monomers - simple sugars (e.g. glucose)

  Polymers - complex carbs (e.g. glycogen or starch)
• Complex carbs are connected by chemical bonds, turning into simple carbohydrates when they are broken.
• Carbs are broken down by enzymes in the

  • mouth
  • small intestine
• PROTEINS COME IN DIFFERENT SIZES

  Monomers - amino acids

  Polymers - protein (which is actually just amino acids bonded together)
• Protein is broken down by enzymes in the

  • stomach
  • small intestine
• Lipids can both fats and oils.
• FAT: solid lipid at room temperature

  OIL: liquid lipid at room temperature
• Lipids are not polymers
• Lipids are broken down by enzymes in the

  • small intestine
• Lipid molecules are made out of:

  • 3 fatty acids
  • 1 glycerol

  The length and structure of these molecules determine if the lipid is a fat or an oil
• Carbohydrates:

  • C, H, O.
• Fats:

  • C, H, O.
  • 3 fatty acids and 1 glycerol.
• Proteins:

  • C, H, O, N.