Stages of digestion 0.0 / 5 ? BiologyEnzymes and digestionGCSEWJEC Created by: Katy **Created on: 31-12-13 10:53 Stage 1 - Mouth Digestion starts with the mechanical digestion by the teeth in the mouth. Then a chemical digestion by saliva starts - carbohydrase digests glusoce 1 of 6 Step 2 - Oesophagus This is a muscular tube (gullet). When you swallow, the food moves to the stomach. The food moves by involentary contractions (peristalsis). 2 of 6 Step 3. - Pancreas & Stomach pH of 2-3 The pancrease will secrete enzymes - lipase, protease & carbohydrase. The stomach will secrete hydrochloric acid that will digest bacteria. 3 of 6 Step 4. - Small Intestine The rest of the enzyme carbohydrase will digest starch into glucose. Protease will digest protein to amino acids. Lipase will digest fats into fatty acids & glycerol. The food molecules have to be small enough to be absorbed throught the wall of the small intestine & into the blood. 4 of 6 Step 5. - Large Instestine The water is reabsorbed into the blood. Fibre is insoluble & cannot be digested, this is why it is stored & then egested through the anus. egested - pushed out 5 of 6 Bile & Liver Liver produces bile (chemical). Bile is stored in the gall bladder Bile has 2 functions - neutralise stomach acid & produce alkaline conditions for enzymes to work in Emulisification converts large fat globules to smaller fat droplets The enzymes produced by the body help digestion. Everything that is digested is absorbed into the blood. 6 of 6
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