Digestion

• What are the main organs in the digestive system?

  The main organs include the mouth, esophagus, stomach, small intestine, and large intestine.
• What are the three main nutrients found in food?

  The three main nutrients are carbohydrates, proteins, and lipids (fats).
• Why must large food molecules be digested?

  They must be digested because they are too large to be absorbed into the bloodstream.
• What role do enzymes play in digestion?

  Enzymes break down large food molecules into smaller molecules.
• What begins the digestion of starch in the mouth?

  Enzymes in the saliva begin to digest starch.
• What is the function of hydrochloric acid in the stomach?

  Hydrochloric acid helps enzymes to digest proteins.
• What happens to food in the stomach?

  The churning action of the stomach muscles turns food into a fluid, increasing the surface area for enzymes to digest.
• What does the pancreas release into the small intestine?

  The pancreas releases enzymes that continue the digestion of starch, protein, and lipids.
• What is the role of bile in digestion?

  Bile helps to speed up the digestion of lipids and neutralizes stomach acid.
• How are small food molecules absorbed in the small intestine?

  Small food molecules are absorbed into the bloodstream by diffusion or active transport.
• What happens in the large intestine?

  Water is absorbed into the bloodstream in the large intestine.
• What is the function of enzymes in the digestive system?

  They catalyze chemical reactions and speed them up
• What is the final product released from the body after digestion?

  The final product released from the body is feces.
• What are enzymes made of?

  Large protein molecules
• How are the products of digestion used by the body?

  The products of digestion are used to build new carbohydrates, lipids, and proteins.
• What is one use of glucose produced during digestion?

  Some of the glucose produced is used in respiration.
• What is the active site of an enzyme?

  It is the groove on the enzyme's surface where the substrate attaches
• What is a substrate in the context of enzymes?

  The molecule that the enzyme breaks down
• What does the lock and key theory describe?

  It describes how the substrate must fit perfectly into the active site of the enzyme
• What is the process of digestion in the digestive system?

  1. Large food molecules are broken down into smaller molecules by enzymes.
  2. Small molecules are absorbed into the bloodstream.
  3. Products of digestion are used to build new carbohydrates, lipids, and proteins.
  4. Glucose is used in respiration.
• What type of enzymes break down proteins?

  Proteases
• Where are proteases found in the digestive system?

  In the stomach and pancreatic fluid in the small intestine
• What are proteins made of?

  Long chains of amino acids
• What happens to proteins during digestion?

  Protease enzymes convert proteins back to individual amino acids
• What type of enzymes break down carbohydrates?

  Carbohydrases
• What is the specific enzyme that breaks down starch?

  Amylase
• Where is amylase found?

  In saliva and pancreatic fluid
• What is the structure of a lipid molecule?

  A lipid consists of a molecule of glycerol attached to three fatty acids
• What enzyme digests lipids?

  Lipase
• What products are formed when lipids are digested?

  Glycerol and fatty acids
• Where is lipase found?

  In pancreatic fluid and the small intestine
• What is the role of bile in lipid digestion?

  Bile emulsifies lipids, increasing their surface area for lipase action
• Where is bile produced and stored?

  Bile is made in the liver and stored in the gallbladder
• How does bile affect the digestion of lipids?

  Bile increases the rate of lipid breakdown by lipase
• What is the pH nature of bile and its effect on stomach acids?

  Bile is alkaline and neutralizes stomach acids
• What are the key enzymes involved in the digestion of food and their functions?

  • Proteases: Break down proteins into amino acids
  • Amylase: Breaks down starch into simple sugars
  • Lipase: Breaks down lipids into glycerol and fatty acids
• What are the roles of bile in digestion?

  • Emulsifies lipids to increase surface area for lipase
  • Neutralizes stomach acids to create alkaline conditions in the small intestine
• How do enzymes and bile work together in the digestive system?

  • Enzymes catalyze the breakdown of food into smaller molecules
  • Bile emulsifies fats, increasing the efficiency of lipase in breaking down lipids
• What is the main function of enzymes?

  Enzymes speed up chemical reactions.
• What is the active site of an enzyme?

  The active site is a groove on the enzyme's surface where the substrate fits.