2.1 Enzymes and Digestion

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  • Created by: maddie
  • Created on: 01-12-12 20:21
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  • 2.1 Enzymes and Digestion
    • Digestive system - long muscular tube and glands - produce enzymes to break food molecules into smaller ones for digestion
    • major parts of digestive system
      • oesophagus - thick muscualr wall - carries food from mouth to stomach - adapted for transportion
      • stomach - muscular sac with inner layer prdocuing enzymes. Stores and digests food, particulalry protein _> produces protease. Has mucus lining- prevent being digested by own enzymes
      • Small itestine - long muscular tube. Digests food using enzymes produced in its walls and glands. Lining has villi and micro villi to increase surface area -> more molecules into bllod stream
      • rectum - final section of intestines. faeces stored here before being excreted by anus during egestion
      • large intestine- absrobs water, mosly from secretions of many digestive glands. Food becomes drier and thicker forming faeces
      • slaivary glands - situated near mouth, passing secretions (containing amalyse to digest starch) via duct into mouth
      • pancreas - gland below stomach, produce pancreaitc jucie conating protease, amalyse & lipase
    • digestion takes place physically or chemically
      • physically
        • food broken to small pieces by structure i.e. teeth. Allows food to be ingested & icreases SA for chemical digestion
        • food churned by stomach muscle to physically break it up
      • chemically
        • enzymes hydralse insoluble molecules to soluble ones
          • enzymes are specific - usually 1 enzymes breaks large molecule into sections then hydrolysed into smaller molecules by another enzyme
          • hydrolysis - splitting of molecules by adding H2O to chemical bonds
        • once molecules hyrolysed absrobed from small intestine into bloo, then carried to body and built up again. Molecules incorprated into body and/0r used in bodily processes - assimilation

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