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isabelle's digestion - Coggle Diagram

- - - - provide twice energy compared carbohydrates the same mass
      - constituent elements
        
        carbon, hydrogen and oxygen
      - source of nutrients
        
        butter, margarine and cheese
      - stored under skin, insulate body from excessive heat loss
    - - for growth new cells and tissues
        
        repair damaged tissues
      - constituent elements
        
        carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus
      - source of nutrients
        
        meat, fish, milk, nuts and eggs
      - energy sources when carbohydrates and fats not available
    - - provide primary source energy for various activities - growth and movement
      - constituent elements
        
        carbon, hydrogen and oxygen
      - source of nutrients
        
        starch (rice), bread noodles, potatoes, different sugar forms in fruits
  - - - will suffer food-borne diseases
        
        symptoms - vomiting, diarrhoea, stomach cramps, fever / others
    - - infections in intestine / produce toxin > bloodstream = infections elsewhere in body
    - - bacteria need time to reproduce more > cause infection
    - - food products handled in hygienic way/stored properly
      - people should wash hands before handling food
- - - - when broken - smaller simple form, they move to intestinal walls >bloodstream>transported all parts of body
        
        large and complex food substances
        
        carbohydrates, fats and proteins
        
        small and simple food substances
        
        glucose, glycerol and fatty acids and amino acids
  - - - large pieces of food into smaller pieces
        
        why important? ..increase surface area
        
        where it happen?
        
        mouth (chewing action)
        
        oesophagus (peristalsis)
        
        stomach (churning action)
        
        small intestine (emulsification)
        
        mouth (starch)
        
        stomach (protein)
        
        small intestine (carbohydrates, fats and protein)
      - identities of food substances - unchanged, no new products formed
    - - process large molecules broken > smaller simple molecules by enzymes
        
        why important? ..allow food substances enter blood > intestinal wall
      - identities of food substances change, new products formed
- - - - shape of food substance fit active site - 'lock and key' model. each enzyme can only break down one type of food
        
        food substance which enzyme acts on, called substrate
        
        enzyme no change after digestion complete
        
        enzyme only break one type of food
  - - - proteases
        
        proteins > amino acids
    - - amylase
        
        starch > maltose
      - lipase
        
        fats > glycerol + fatty acids
      - maltase
        
        maltose > glucose
      - carbohydrates
        
        carbohydrates > glucose
      - proteases
        
        proteins > amino acids
    - - salivary amylase
        
        starch > maltose
- - - - important events along alimentary canal
        
        mouth
        
        place where food received into human body > ingestion
        
        physical digestion by action of teeth
        
        food chewed help of teeth > cut, grind > smaller pieces
        
        increase surface area, allow enzymes digest it faster
        
        chemical digestion by salivary amylase
        
        starch digested > maltose by salivary amylase
        
        oesophagus
        
        muscular tube moves food from mouth > stomach
        
        through alternate waves of relaxation, contraction of muscular walls
        
        movement called peristalsis
        
        food present is called bolus
        
        stomach
        
        j-shaped, sac-like muscular organ, at upper part abdomen
        
        physical digestion by churning action
        
        by muscular wall of stomach > food break into smaller pieces
        
        helps food mix with gastric juice
        
        chemical digestion by proteases
        
        proteins digested into amino acid by proteases
        
        gastric juice contain water, hydrochloric acid, proteases
        
        hydrochloric acid two important function
        
        kill bacteria in food
        
        provide acidic environment > proteases work effectively
        
        food stays in stomach > 2 - 6 hours, partly digested food > chyme
        
        small intestine
        
        long muscular tube, has average length > 6 metres
        
        liver, gall bladder, pancreas associate with it
        
        physical digestion through emulsification
        
        bile produced by liver, stored in gall bladder
        
        released into small intestine when fats reach region
        
        bile not enzyme. substance break up fat molecules > fat globules
        
        process called emulsification
        
        emulsification increase surface area fat molecule, digested by lipase faster
        
        chemical digestion by various enyzymes
        
        pancreas secretes pancreatic juice, small intestine secretes intestinal juice
        
        they contain various enzymes > amylase, maltase, carbohydrates, proteases, lipase
        
        absorption of food
        
        take place in small intestine
        
        surface of small intestine > finger-like structures > villi (singular: villus)
        
        final products of digestion
        
        glucose, amino acids, fatty acids, glycerol enter bloodstream > villus
        
        walls > lining of cells (epithelial cells), only one-cell thick wall
        
        allow absorption of food quickly
        
        food substances enter bloodstream > diffusion / active transport
        
        large intestine
        
        large intestine average length > 1.5 metres
        
        in colon of large intestine, water, mineral salts absorbed > body
        
        solid waste (faeces) stored in rectum temporarily
        
        expelled > anus by process called egestion