The Digestive System + Enzymes

• What is a tissue?

  A group of cells with a similar structure and function.
• What is an organ?

  A group of tissues that work together to perform a specific function in the body.
• What is an organ system?

  Works together to from organisms.
• What are the three main nutrients?

  Carbohydrates, proteins, lipids.
• What are enzymes absorbed into?

  Bloodstream.
• What breaks down large molecules into small molecules?

  Enzymes.
• What is the order of the human digestive system?

  Mouth, oesphagus, stomach, small intestine, large intestine, rectum, anus.
• What is the role of the mouth in digestion?

  Enzymes in saliva digest starch into smaller molecules.
• What is the role of the oesophagus in digestion?


  To transport food to the stomach.
• What acid in the stomach helps to digest proteins?

  Hydrochloric acid.
• How does the churning of stomach muscles help food to digest?

  Churns food into a fluid, increasing the surface area for enzymes to digest.
• What organs release chemicals into the small intestine?

  Liver and pancreas.
• What does the pancreas release into the small intestine?

  Enzymes to continue the digestion of starch and protein. This also starts the digestion of lipids.
• What does the liver release into the small intestine?

  Bile.
• What is the role of bile in the digestive system?

  Neutralises HCL.

  Speeds up the digestion of lipids.

  Emulsifies.
• Where is bile stored?

  Gallbladder.
• How are small molecules absorbed into the blood stream from the small intestines?

  Diffusion or active transport.
• What is the role of the large intestine within the digestive system?


  Allows water to be absorbed into the bloodstream.
• What is the final stage of the digestive system?

  Faeces is released from the body.
• What are the products of digestion used to build?

  New carbohydrates, proteins and lipids.
• Some glucose produced from digestion is used in respiration.
• What do enzymes do?

  Catalyse chemical reaction.
• What does the substrate attach to?


  The active site of the enzyme.
• What are proteins broken down by?

  Proteases.
• Where is protease found within the body?


  The stomach, pancreas and small intestine
• What are long chains of proteins called?

  Amino acids.
• What breaks down carbohydrates?

  Carbohydrase.
• What breaks down starch?

  Amylase.
• What is starch a chain of?

  Glucose molecules.
• Where is amylase found?

  Amylase is found in the saliva and pancreas.
• What do digested carbohydrates produce?

  Simple sugars.
• What are lipids broken down by?


  Lipase.
• What does a lipid molecule consist of?

  One glycerol molecule and three molecules of fatty acids.
• Where is lipase found?


  Lipase is found in the pancreas and in the small intestine.
• What happens to an enzyme when the temperature increases?

  As the temperature increase so does the activity of the enzyme?
• Why does an enzyme increase in activity when the temperature increases?

  There are more collisions between the active site (enzyme) and the substrate.
• What happens to an enzyme when it is working at the optimum temperature?

  Fastest possible rate and maximum frequency.
• What happens to an enzyme when the temperature increases past the optimum rate?

  It denatures.
• What does denatured mean?

  The active site changes shape, meaning the substrate no longer fits.
• What happens to enzyme when the pH is made more acidic or alkaline?

  It denatures.