chapter 4

• What are the chemical elements present in carbohydrates?

  Carbon, Oxygen, and Hydrogen
• What are the chemical elements present in proteins?

  Carbon, Oxygen, Hydrogen, Sulfur, Nitrogen, and Phosphorus
• What are the chemical elements present in lipids?

  Carbon, Oxygen, and Hydrogen
• What are the basic units that make up carbohydrates, proteins, and lipids?

  • Carbohydrates: Simple sugars (e.g., glucose)
  • Proteins: Amino acids
  • Lipids: Fatty acids and glycerol

  
• What is the method for testing glucose using Benedict's solution?

  Add Benedict's solution and heat
• What is the method for testing starch using iodine solution?

  Add iodine solution to the sample
• What color indicates the presence of starch in the iodine test?

  black
• What color indicates the presence of glucose in the Benedict's test?

  Brick red
• What is the method for testing protein using biuret solution?

  Add biuret solution and wait
• What color indicates the presence of protein in the biuret test?

  Violet
• What is the method for testing fat?

  Mix with ethanol and water
• What indicates the presence of fat in the fat test?

  Milky-white emulsion forms
• What components should a balanced diet include?

  • Carbohydrates
  • Proteins
  • Lipids
  • Dietary fiber
  • Vitamins
  • Minerals
  • Water
• Why is a balanced diet important for humans?

  To maintain good health
• What is the function of carbohydrates in the diet?

  Used for energy
• What is a source of carbohydrates?

  Rice, potatoes, pasta, breads
• What is the function of protein in the diet?

  Growth and repair
• What is the function of Vitamin A?

  Healthy eyesight
• What is a source of Vitamin A?

  Carrots
• What is the function of Vitamin C?

  Forms collagen protein
• What is a source of Vitamin C?

  Citrus fruits
• What is the function of Vitamin D?

  Strengthen teeth and bones
• What is a source of Vitamin D?

  Margarine
• What is the function of lipids in the diet?

  Insulation and energy storage
• What is a source of lipids?

  Nuts, seeds, meats
• What is the function of dietary fiber?

  Lower cholesterol
• What is a source of dietary fiber?

  Vegetables, whole grains
• What is the function of calcium?

  Strengthen bones, teeth, and muscles
• What is a source of calcium?

  Milk
• What is the function of iron?

  Used to make hemoglobin
• What is a source of iron?

  Meat
• What is the function of water in the diet?

  Chemical reactions to take place
• What is the explanation for energy requirements increasing with age?

  Needed for growth towards adulthood
• How do activity levels affect energy requirements?

  More active requires more energy
• Why do energy requirements increase during pregnancy?

  Needed for fetal growth and mother's mass
• What is the structure and function of the human alimentary canal?

  • Passage for food from mouth to anus
  • Breaks food into absorbable molecules
  • Mechanical digestion: Chewing and churning
  • Chemical digestion: Using enzymes
• What is the function of the mouth in digestion?

  Mechanical digestion occurs here
• What is the role of saliva in the mouth?

  Lubricates food and contains amylase
• What is the function of the oesophagus?

  Connects mouth to stomach
• What is peristalsis?

  Wave-like contractions pushing food down