B3

• What are the five levels of organization in living organisms?

  Cells, tissues, organs, organ systems, organisms
• What are cells considered in the organization of living organisms?

  Basic building blocks
• What do tissues consist of?

  Groups of cells with similar structures
• What do organs do in the organization of living organisms?

  Groups of tissues working together
• What is the role of organ systems?

  Groups of organs working together
• What do organ systems form when they work together?

  An organism
• What is the function of enzymes?

  They catalyse (speed up) reactions
• How are enzymes affected during the reactions they catalyse?

  They are not changed
• What does the lock and key theory describe?

  How enzymes work with specific substrates
• What is the active site of an enzyme?

  Where the reaction occurs
• What happens at the active site of an enzyme?

  Enzymes can break down or bind molecules
• What occurs after the products are released from an enzyme?

  The active site can accept another substrate
• What is the function of the mouth in digestion?

  Where food is chewed
• What do salivary glands produce?

  Saliva containing amylase
• What is the role of the oesophagus?

  It carries food to the stomach
• What are the functions of the stomach?

  Churns food, releases protease, and acid
• What does hydrochloric acid do in the stomach?

  Kills pathogens
• What does the liver produce?

  Bile
• What is the function of the gall bladder?

  Stores bile
• How does bile assist in digestion?

  Neutralizes acid and emulsifies fat
• What enzymes does the pancreas produce?

  Amylase, lipase, and protease
• Where is digested food absorbed?

  In the small intestine
• What is the function of the large intestine?

  Absorbs water and minerals
• What does the rectum do?

  Stores faeces
• What is the function of the anus?

  Expels faeces
• What do digestive enzymes do?

  Convert food into small, soluble molecules
• What do carbohydrases break down?

  Carbohydrates into simple sugars
• What are the sites of production and reactions catalysed by amylase?

  • Sites of production: salivary glands, pancreas, small intestine
  • Reaction catalysed: starch ➞ glucose
• What are the sites of production and reactions catalysed by proteases?

  • Sites of production: stomach, pancreas, small intestine
  • Reaction catalysed: proteins ➞ amino acids
• What are the sites of production and reactions catalysed by lipases?

  • Sites of production: pancreas, small intestine
  • Reaction catalysed: lipids ➞ fatty acids and glycerol
• How does pH affect enzymes?

  Different enzymes have different optimum pH values
• What is the optimum pH for protease?

  In stomach acid
• What is the optimum pH for amylase?

  In neutral saliva
• How does temperature affect enzyme activity?

  Increased temperature raises reaction rates
• What happens to an enzyme at high temperatures?

  It becomes denatured and stops working
• What is denaturation in enzymes?

  Change in the shape of the active site
• What happens when an enzyme is denatured?

  The substrate can no longer bind to the active site
• What are the key terms related to enzymes and digestion?

  • Active site
  • Amylase
  • Catalyse
  • Denatured
  • Enzyme
  • Lipase
  • Optimum
  • Organ
  • Organ system
  • pH
  • Protease
  • Substrate
  • Temperature
  • Tissue