Nutrition

• Photosynthesis


  1. Converts light energy into chemical energy (glucose)

  2. 6CO2 + 6H2O → C6H12O6 + 6O2
• Photosynthesis


  • Provides energy for plants and oxygen for other organisms
• Photosynthesis Equations


  • Word Equation: Carbon dioxide + water → glucose + oxygen
  • Chemical Equation: 6CO2 + 6H2O → C6H12O6 + 6O2
• Factors Affecting Photosynthesis


  • Carbon Dioxide Concentration
  • Light Intensity
  • Temperature
• Structure of the Leaf

  • Large surface area, thin, chloroplasts in palisade layer, stomata for gas exchange
• Magnesium Ions


  Needed for chlorophyll
• Nitrate Ions


  Needed for amino acids and proteins
• Investigate Photosynthesis


  Use a water plant (e.g., Elodea) to show oxygen production, test leaves for starch, and observe effects of light, CO₂, and chlorophyll
• Balanced Diet Components


  • Carbohydrates
  • Proteins
  • Lipids
  • Vitamins
  • Minerals
  • Water
  • Dietary Fibre
• Carbohydrates


  Energy source
• Proteins


  Growth and repair
• Lipids


  Energy storage, insulation
• Vitamins


  • A: Vision, immune function
  • C: Skin, gums, immune function
  • D: Calcium absorption, bone health
• Minerals


  • Calcium: Bone and teeth health
  • Iron: Hemoglobin in blood
• Water


  Hydration, bodily functions
• Dietary Fibre


  Digestion, prevents constipation
• Energy Requirements


  Depends on activity levels, age, and pregnancy
• Structure and Function of the Alimentary Canal

  • Mouth: Mechanical digestion, saliva
  • Oesophagus: Transports food to stomach
  • Stomach: Chemical digestion, acid
  • Small Intestine: Nutrient absorption
  • Duodenum: Digestion
  • Ileum: Absorption
  • Large Intestine: Water absorption
  • Colon: Absorbs water
  • Rectum: Stores feces
  • Pancreas: Produces digestive enzymes
• Peristalsis


  Wave-like muscle contractions move food through the gut
• Digestive Enzymes


  • Amylase and Maltase: Starch to glucose
  • Proteases: Proteins to amino acids
  • Lipases: Lipids to fatty acids and glycerol
• Bile


  Produced by liver, stored in gall bladder, neutralizes stomach acid, emulsifies lipids
• Absorption in the Small Intestine

  • Villi and microvilli increase surface area for absorption
• Investigate Energy Content in Food

  Burn food samples to measure energy released