Organic molecules

• Sugars


  Small units that all carbohydrates are made of
• Types of sugars


  • Reducing sugars
  • Non-reducing sugars
• Starch


  A type of carbohydrate that is a larger and more complex molecule than sugars
• Proteins


  Tested using the Biuret test
• Main groups of nutrients needed

  • Carbohydrates (like starch and glucose)
  • Proteins
  • Fats
• Role of digestion


  To break all this food down into tiny pieces so that we can absorb it into our body cells
• Biological molecules/nutrients covered


  • Carbohydrates
  • Lipids
  • Proteins
  • Vitamins
  • Mineral ions
  • Fiber
  • Water
• Mouth


  1. Food placed in mouth

  2. Broken down physically by chewing

  3. Saliva released from salivary glands

  4. Saliva contains salivary amylase to break down carbohydrates
• Esophagus


  Food swallowed and passes down
• Stomach


  1. Muscular sac that contracts to push and mix food

  2. Produces pepsin enzyme to break down proteins

  3. Produces hydrochloric acid to kill bacteria and provide right environment for pepsin
• Carbohydrates


  Found most in starchy foods like bread, pasta, and potatoes, as well as in fruits and vegetables. Provide energy for chemical reactions and movement.
• Lipids


  Fats and oils. Provide energy, insulate us, and protect our organs.
• Small intestine


  1. Digested food absorbed into bloodstream

  2. Site of most digestion

  3. Produces own digestive enzymes

  4. Pancreas produces and releases digestive enzymes into small intestine

  5. Gallbladder releases bile to neutralize stomach acid and emulsify fats
• Proteins


  Found in nuts, seeds, meat, fish, and legumes. Act as building blocks for growth and repair of damaged tissue. Can also be used for energy.
• Lining of small intestine

  • Villi (finger-like projections) to increase surface area
  • Single layer of surface cells for short diffusion distance
  • Good blood supply to maintain concentration gradient
• Large intestine


  1. Absorbs excess water from leftover material

  2. Stores feces in rectum until removal
• Vitamins


  Organic molecules made by living organisms. Needed in small amounts for various bodily functions.
• Recap of digestive process order

  • Food placed in mouth
  • Chewed and mixed with saliva
  • Swallowed down esophagus
  • Enters stomach
  • Pushed into small intestine
  • Digested and absorbed into bloodstream
  • Leftover material enters large intestine
  • Water absorbed, feces stored in rectum
• Vitamin A


  • Found in liver and leafy vegetables. Needed for good vision, skin, and hair health.
• Vitamin C


  • Found in fruit and vegetables, especially citrus fruits. Prevents scurvy.
• Vitamin D


  • Can be made by the body using sunlight, also found in eggs and oily fish. Helps absorb calcium.
• Minerals


  Inorganic, simple molecules. Needed in small amounts for various bodily functions.
• Calcium


  • Found in dairy products and leafy vegetables. Needed for strong bones.
• Iron


  • Found in red meat, spinach, and beans. Component of hemoglobin that transports oxygen.
• Fiber


  Type of carbohydrate not absorbed by the body. Helps food move through the intestines properly.
• Benedict`s Test Results

  If Glucose present: Brick-Red Solution

  If Glucose not present: Blue solution
• Biuret`s Test Results

  If Proteins Present: Purple Solution

  If Proteins not Present: Blue Solution
• Ethanol Test Result

  If Lipid`s Present: Cloudy Solution

  If Lipids`s Not Present: Clear Solution
• Iodine Test Results

  If Starch is present: Blue Black Solution

  If Starch is not present: Brown Solution