Organisation

• What do we call connected similar cells?

  Tissue
• What do tissues form in the body?

  Organs
• What do organs work together to form?

  Organ systems
• What is the function of the digestive system?

  Breaks down food into nutrients
• What breaks down food in the stomach?

  Acid
• What works together in the small intestine to break down food?

  Bile and enzymes
• Where is bile made?

  Liver
• What is the role of bile in digestion?

  Neutralizes stomach acid and emulsifies fats
• What do enzymes do?

  Act as biological catalysts
• What is amalay's function?

  Breaks down starch into glucose
• Where is amalay found?

  Small intestine and saliva
• What is the specificity of enzymes?

  They only break down certain molecules
• What do carbohydrases break down?

  Carbohydrates into simple sugars
• What do proteases break down?

  Proteins into amino acids
• What do lipases break down?

  Fats into glycerol and fatty acids
• What principle explains enzyme specificity?

  Lock and key principle
• What happens when a substrate binds to an enzyme?

  A complex is formed
• What is required for the substrate to fit the enzyme's active site?

  The right shape
• What happens to enzyme activity as temperature increases?

  It increases until denaturation occurs
• What is denaturation in enzymes?

  Change in active site shape
• What is the optimum temperature for enzyme activity?

  The temperature for maximum rate
• How does pH affect enzyme activity?

  It can denature enzymes at extremes
• What is the practical method to test enzyme activity with starch?

  1. Mix amalay with starch at different temperatures or pH.
  2. Start timing and remove drops every 10 seconds.
  3. Use iodine to test for starch presence.
  4. Record time until iodine stays orange.
  5. Plot times against pH or temperature.
  6. Identify optimum conditions from the graph.
• What color does iodine turn in the presence of starch?

  Black
• What color does Benedict's solution turn in the presence of sugars?

  Orange
• What color does Biuret's reagent turn in the presence of proteins?

  Purple
• What happens to cold ethanol in the presence of lipids?

  It turns cloudy
• What is the respiratory system responsible for?

  Breathing and gas exchange
• How does breathing relate to respiration?

  Breathing provides oxygen for respiration
• What is the pathway of air during breathing?

  Trachea, bronchi, bronchioles, alveoli
• What is the function of alveoli?

  Gas exchange with blood vessels
• What happens to oxygen in the blood?

  It binds to hemoglobin in red blood cells
• How is carbon dioxide removed from the body?

  It diffuses into the lungs and is exhaled
• What is the heart's role in the circulatory system?

  It pumps blood throughout the body
• What type of circulatory system do humans have?

  Double circulatory system
• How many times does blood enter the heart in a double circulatory system?

  Twice
• What vein carries deoxygenated blood to the heart?

  Vena cava
• What prevents backflow of blood in the heart?

  Valves
• Where does deoxygenated blood go after the right atrium?

  Right ventricle
• What happens to deoxygenated blood in the lungs?

  It gets oxygenated