digestive system

• 1st stage: food enters the mouth and is broken down by the act of chewing. Digestion begins by the amylase enzymes in saliva.
• 2nd stage: the food moves through to the stomach down the oesophagus.
• 3rd stage: the food enters the stomach, a muscular organ that holds the food while the pancreas produces digestive enzymes, carbohydrase, lipase and protease. the stomachs muscles relax and contract to mix the food. the stomach also produces hydrochloric acid which kills bacteria,
• • the stomach contracts its walls, produces pepsin. to break don protein, and hydrochloric acid to kill bacteria
• stage 4: after being in the stomach the food is squeezed into the small intestine which is where the food is absorbed into the bloodstream
• the small intestine produces enzymes to help digestion. A lot of the digestion happens in the small intestine. The pancreas produces most of the digestive enzymes and through pancreatic juices is taken to the small intestine.
• The gallbladder releases bile which is used to neutralise acid from the stomach which makes the pH more ideal for enzymes is alkaline. It also helps emulise fat which turns large pieces of fat into small pieces gives the digestive enzymes a larger surface area to work. bile is made the liver but stored in the gallbladder.
• The small intestine is lined by villi which increases its surface area which helps with absorption of the food into the bloodstream. The villi have a single layer of cells on the surface, which means nutrients only have to diffuse a short distance
• stage 5: the large intestine absorbs water and electrolytes from the food and creates waste
• 1. mouth
  2. oesophagus
  3. stomach
  4. small intestine
  5. large intestine
  6. rectum
  7. anus
• The digestive system is used to Breakdown large food molecules into smaller molecules which is known as digestion. It was also used to absorb small food molecules into the body which is known as absorption.
• The salivary glands in our mouth release saliva which lubricates the food and makes it easier to swallow. It also contains the enzyme amylase which breaks down starch into maltoes.
• The Benedict test is for sugars
• The iodine test is for starch
• The Biuret test is for proteins