Orginisation

• What makes up all living things?

  Cells
• What is a tissue?

  A group of specialized cells with similar function
• Can tissues be made of more than one type of cell?

  Yes
• How are organs formed?

  From different tissues working together
• What do organs work together to produce?

  A specific function
• What organ system is the stomach part of?

  The digestive system
• What is the function of the digestive system?

  To break down food for absorption
• What type of food needs to be broken down?

  Large and insoluble food
• What do glands produce in the digestive system?

  Digestive juices containing enzymes
• What is the role of the stomach in digestion?

  Produces hydrochloric acid
• Why does the stomach produce hydrochloric acid?

  To kill bacteria and optimize pH
• Where are soluble molecules absorbed?

  In the small intestine
• What does the liver produce for digestion?

  Bile
• Where is bile stored?

  In the gallbladder
• What does the large intestine absorb?

  Water from undigested food
• What is produced from the absorption of water in the large intestine?

  Faeces
• How does faeces exit the body?

  Through the rectum and anus
• What are enzymes?

  Biological catalysts
• What do enzymes do?

  Increase the rate of reaction
• How do enzymes interact with molecules?

  They break up large molecules and join small ones
• What type of molecules are enzymes?

  Protein molecules
• Why is the shape of an enzyme important?

  It is vital to its function
• What is an active site?

  The uniquely shaped area where substrate binds
• What happens when the substrate binds to the active site?

  An enzyme-substrate complex is formed
• What is required for enzymes to function properly?

  Optimum pH and temperature
• What is the optimum temperature for most enzymes?

  Around 37 degrees Celsius
• What happens to the rate of reaction as temperature increases?

  It increases up to the optimum
• What occurs if the temperature exceeds the optimum?

  The enzyme denatures and stops working
• What does denatured mean in relation to enzymes?

  The enzyme can no longer work
• What is the optimum pH for most enzymes?

  7
• What happens if the pH is too high or too low?

  The enzyme denatures and stops working
• Why are enzymes vital in the digestive system?

  They break down molecules for absorption
• What are carbohydrases?

  Enzymes that convert carbohydrates into sugars
• Where is amylase produced?

  Salivary glands, pancreas, small intestine
• What do proteases convert?

  Proteins into amino acids
• Where is pepsin produced?

  In the stomach
• What do lipases convert?

  Lipids into fatty acids and glycerol
• Where are lipases produced?

  In the pancreas and small intestine
• What happens to soluble glucose, amino acids, fatty acids, and glycerol?

  They pass into the bloodstream
• How are nutrients used in the body?

  To build new carbohydrates, lipids, and proteins