Macromolecules

• Macromolecules


  Needed in large quantities to provide energy, large molecules made up of smaller ones linked together
• Types of macromolecules


  • Carbohydrates
  • Proteins
  • Lipids
  • Nucleic acids
• Carbohydrate digestion


  Digested in mouth, any sugars from starch, digested in small intestine with pancreatic amylase
• Protein digestion


  Broken down by pepsin in stomach, hydrolyzed by pancreatic enzymes in small intestine
• Lipid digestion


  Broken down by bile salts and pancreatic lipases in small intestine
• Nucleic acid digestion


  Broken down by nucleases in small intestine
• Macromolecules must be broken down before they can be absorbed by the body
• Protein breakdown


  Polypeptide -> dipeptide -> amino acids
• Lipid breakdown


  Glycerol + fatty acids
• Lipids


  • Provide better energy than carbohydrates, more energy per gram
• Macromolecule functions


  • Carbohydrates: provide materials to build cell membranes, quick energy source for cells
  • Proteins: build and repair muscles and cell membranes, involved in muscle movement like contraction, provide structure and support for body tissues
  • Lipids: build cell membranes, insulate body, energy storage, protect organs from injury