10.1 Nutrition & Digestion

• The chemicals from the food you eat are used to…

  1. Provide building blocks to build molecules
  2. Generate energy for your body
  3. Assemble essential nutrients your body cannot produce
• Nutrients: Chemicals in food that help your body perform all its functions
• What are the 6 types of nutrients?

  Carbohydrates, proteins, fats, vitamins, minerals, water.
• Macronutrients: Body needs a lot of on a daily basis.

  • Carbohydrates, proteins, fats, and water
• Micronutrients: Body doesn’t need as much.

  • Vitamins, minerals, and other nutrients that are required in small amounts
• Digestive system breaks down large food molecules into smaller ones (a.k.a. “building block”), so your cells can utilize the molecules.
• Carbohydrates break down into glucose
• Proteins break down into amino acids
• Lipids break down into fatty acids + glycerol
• Your cells than use the building blocks to assemble your own nutrients
• Carbohydrates are made of carbon, hydrogen and oxygen.
• Carbohydrates are a major source of energy for the body. Can use the energy immediately or store it for later use
• Glucose: Main sugar fuel supply molecule in the body.
• Body breaks down glucose and extracts it’s energy (ATP)
• Glucose not used immediately are incorporated into larger (complex) carbs like glycogen, or used to make fat molecules
• Starches (e.g. cereal, bread, rice, potatoes) are called complex carb
• Complex carbs are broken down into simpler sugars by the digestive system.
• Simple sugars are absorbed into blood and carried to cells of the body
• Excess blood sugar is converted into glycogen (chain of many glucose molecules) and stored in the liver,

  muscle and fat cells
• When the body needs energy, it breaks down glycogen, releasing glucose…ATP
• Cellulose is a complex carb called fibre found in plants.
• Human digestive system cannot break

  down cellulose, but you still need it!
• Fibre helps your muscles move food and wastes through your digestive system, and reduce the risk of heart disease
• Monosaccharides: Single sugar molecule
• Disaccharides: Contains two saccharide molecules
• Polysaccharides: More than two linked sugar molecules
• Monosaccharide/Disaccharide: Provides a quick source of energy
• Polysaccharide: Stores energy,

  provides structural support to cells
• Enzymes: Proteins that speed up specific chemical reactions without being consumed in the reaction

  (e.g. lactase helps break down lactose)
• Proteins: Complex molecule made from 20 kinds of smaller molecules called amino acids.
• What are the functions of proteins?


  They have many functions such as provide long-term nutrient storage (e.g. muscles), defend the body from harmful microorganisms, messengers, and work with enzymes to control chemical reactions in a cell.
• There are 8 essential amino acids (body can’t produce on its own)

  • Meat, milk, eggs, and cheese provide all 8
• Vegetarians and vegans must eat a combination of plant foods to obtain all 8 (e.g. corn, beans, rice, lentils, and hummus)
• Fats: Formed from fatty acids and glycerol
• Fats are also called lipids
• What are the functions of fats?


  They store energy and help your body absorb fat-soluble vitamins and the tissue cushions the organs and provides the body with insulation.
• What are the types of fats?


  Saturated, unsaturated, trans.
• Saturated Fats: Only single bonds between carbon and hydrogen atoms
• Saturated fats can build-up fat deposits within blood vessels reducing blood flow and contributing to heart disease
• Only a small % of daily intake should come from saturated fats