Organisation Video

• What is meant by a tissue?

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

  A group of tissues working together
• What is an organ system?

  A group of organs working together
• What is the main function of the digestive system?

  To break down food and absorb nutrients
• What are the three main nutrients found in food?

  Carbohydrates, proteins, and lipids
• Why must large food molecules be digested?

  They are too large to be absorbed directly
• What role do enzymes play in digestion?

  They break down large molecules into smaller ones
• What begins the digestion of starch in the mouth?

  Enzymes in saliva
• What is the function of hydrochloric acid in the stomach?

  It helps enzymes digest proteins
• What happens to food in the stomach?

  It is churned into a fluid for digestion
• What does the pancreas release into the small intestine?

  Enzymes for digestion
• What is the role of bile in digestion?

  It speeds up lipid digestion and neutralizes acid
• How are small food molecules absorbed in the small intestine?

  By diffusion or active transport
• What happens in the large intestine?

  Water is absorbed into the bloodstream
• What is released from the body at the end of digestion?

  Feces
• How are the products of digestion used by the body?

  To build new carbohydrates, lipids, and proteins
• What is one use of glucose produced during digestion?

  It is used in respiration
• What are the main functions of the organs in the digestive system?

  • Mouth: Chews food and begins starch digestion
  • Stomach: Digests proteins and churns food
  • Small intestine: Continues digestion and absorbs nutrients
  • Large intestine: Absorbs water and forms feces
• What is the role of enzymes in the digestive process?

  • Break down large food molecules
  • Facilitate absorption of nutrients
  • Enable chemical reactions in digestion
• What nutrients are absorbed into the bloodstream after digestion?

  • Small carbohydrates
  • Amino acids from proteins
  • Fatty acids and glycerol from lipids
• What is the process of digestion from mouth to large intestine?

  1. Food is chewed in the mouth
  2. Enzymes in saliva digest starch
  3. Food passes down the esophagus to the stomach
  4. Stomach digests proteins and churns food
  5. Small intestine digests starch, proteins, and lipids
  6. Large intestine absorbs water and forms feces
• What should you be able to describe by the end of the video?

  Enzymes in the digestive system
• What is the role of bile in digestion?

  It helps speed up lipid digestion
• What do enzymes do in the digestive system?

  They catalyze chemical reactions
• What are enzymes made of?

  Large protein molecules
• What is the active site of an enzyme?

  It is where the substrate attaches
• What is the substrate in enzyme reactions?

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

  Enzyme specificity for substrates
• What type of enzymes break down proteins?

  Proteases
• Where are proteases found in the body?

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

  Amino acids
• What happens to proteins during digestion?

  They are converted to 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 starch?

  A chain of glucose molecules
• What is the structure of a lipid molecule?

  Glycerol and three fatty acids
• What enzyme digests lipids?

  Lipase
• What does lipase produce when it digests lipids?

  Glycerol and fatty acids
• Where is lipase found?

  In pancreatic fluid and small intestine