Organisation and digestive systems

• What are the five levels of organisation?

  Cells, tissues, organs, organ systems, organisms
• What is a tissue?

  A group of cells with similar structures
• What is an organ?

  A group of tissues working together
• What is the function of the liver in digestion?

  Produces bile to emulsify fat
• What is the function of saliva in digestion?

  Lubrication to help swallowing
• Name three enzymes produced in the pancreas.

  Amylase, protease, lipase
• What are enzymes?

  Protein molecules that catalyse reactions
• Why are enzymes described as specific?

  Each enzyme fits only certain substrates
• Describe the function of amylase.

  To break down starch into glucose
• Where is amylase produced?

  Salivary glands, pancreas, small intestine
• Describe the function of proteases.

  To break down proteins into amino acids
• Where are proteases produced?

  Stomach, pancreas, small intestine
• Describe the function of lipases.

  To break down lipids into fatty acids
• Where are lipases produced?

  Pancreas and small intestine
• What are two factors that affect enzyme activity?

  Temperature and pH
• What does denatured mean?

  Shape of enzyme's active site is changed
• Describe the effect of temperature on enzyme activity.

  Increases until optimum, then decreases
• Describe the effect of pH on enzyme activity.

  Different enzymes have different optimum pHs
• Why do different digestive enzymes have different optimum pHs?

  Different parts of the digestive system vary in pH
• What is an organ system?

  A group of organs working together