Human digestive enzymes

• Enzymes in the digestive system help you to digest food
• An enzyme is a biological catalyst.

  This means it speeds up a reaction.

  An enzyme isn’t changed or used upin a reaction.
• Digestive enzymes help to break down (digest) large food molecules into smaller, soluble molecules.

  These molecules are smaller so can be absorbed into the bloodstream.
• enzymes have an optimum temperature and pH level.

  Below the optimum temperature, the reaction rate will be slower.

  Enzymes are denatured (damaged) if the temperature is too high.
• The reaction is also slower if the pH is too high (alkaline) or too low (acidic).
• Each enzyme has an active site (the lock) that a particular molecule fits into.

  The molecule that fits into the enzyme (the key) is called the substrate.

  The enzyme locks onto the substrate, which then breaks apart to create the products.
• Amylase is made in the salivary glands, the pancreas and the small intestine.
• Proteases are made in the pancreas, the stomach and the small intestine.
• Lipases are made in the pancreas and the small intestine.
• Bile is made in the liver and helps the body digest fats.

  Bile emulsifies fats.
• The gall bladder stores the bile and thenreleases it into the small intestine after a meal.
• The bile is alkaline and neutralises the hydrochloric acid from the stomach.
• Digestive enzyme break down food molecules so that they are small enough to absorbed into the bloodstream
• Hydrochloric acid is produced in the stomach
• Neutralization raises the acidic pH to a neutral pH 7.)
• The body system responsible for transporting blood around the body is the circulatory system
• Carbon dioxide is a waste product that the body needs to get rid of.
• Humans have a double circulatory system with two separate circulations of blood.
• Where valves are present in the circulatory system they ensure that the blood flows in the correct direction
• Arteries have thick muscular walls to withstand the high pressure of blood that flows through them
• Health is the state of physical and mental well-being.
• The faulty heart valve may not open fully, making the blood circulation inefficient.
• The roots are plant organs specialised to absorb water from the soil.