F212 Unit 2: Food and Health

F212 Unit 2: Food and Health

1. Response to disease

   • specific immune response
     • produces antibodies
       • immunoglobulins - large proteins w/ specific shape complimentary to antigen of pathogen
       • structure= 4 polypeptide chains joined w/ disulfide bridges
         • constant region - heavy polypeptide chain - enables antibody to attach to pathogen -helps in phagocytosis
         • Variable region - ARMS - specific shape complimentary to antigen - bind to pathogen
         • Hinge region- flexibility - allow antibody to attach to more than one antigen
       • NEUTRALISATION - antibodies cover pathogen binging sites - prevent pathogen from binding to host cell or entering
       • AGGLUTINATION - Large antibody binds with many pathogen - group becomes too large to enter host cell
     • gives immunity to the disease bc produces immunological memory release of memory cells
   • non specific response
     • phagocytes
       • phagocytosis
         • phagocyte identifies foreign antigen
           • cytoplasm moves around pathogen engulfing it
             • pathogen in phagocytic vacuole
               • lysosome fuses w/ phagocytic vacuole
                 • digestive enzymes break down pathogen, absorbed into cytoplasm
                   • phagocyte presents foreign antigens of pathogen
                     • activate other immune system cells
       • neutrophils
       • macrophages
         • Antigen Presenting Cells
           • incorporate antigen of pathogen into a cell surface molecule

2. Plants and animals as food

   • microorganisms spoil food
     • keeping food fresh
       • salting = inhibits growth of microorganisms by decreasing water potential gradient of water into cell

3. Disease

   • Effects of lifestyle
     • diet
       • obesity
         • cancer
         • cardiovascular disease
         • type 2 diabetes
       • CHD
         • due to atherosclerosis (deposit of fatty substances in walls of coronary arteries)
           • narrows lumen
             • restricts blood flow
               • can cause oxygen starvation
         • Increase Risk
           • excess salt
           • fats
             • saturated fats = low density lipoproteins
               • animal fats
           • cholesterol
             • stabilizes plasma membranes & is found in the skin
             • insoluble in water tf must be transported in form of lipoproteins
               • LP's are combinations of fats, proteins and CHOLESTEROL
               • HDL'S
                 • unsaturated fats, cholesterol and protein
                 • body tissue back to liver
                   • used in cell metabolism - to make bile
                   • broken down
                     • reduce blood cholesterol levels
                 • polyunsaturated fats = increase activity of LDL receptors = decrease concentration of LDL's
                   • reduce blood cholesterol levels
                 • monounsaturated fats help remove LDL's from blood
               • LP's are released into blood and are taken up by cells that have the correct receptor sites
         • Decrease risk
           • dietary fibre
           • moderate alcohol consumption
           • oily fish
     • smoking
   • pathogenic organisms
     • fungi
       • Trichopyton rubrum = athletes foot
     • bacteria
       • Mycobacterium Tuberculosis = TB
     • viruses
       • Human Immunodeficiency Virus = HIV = AIDS
     • proctists

4. microorganisms to make food

   • need for conservation
   • improving growth of plants and animals
   • Yoghurt- lactobacillus bacteria uses lactose sugar in milk to make lactic acid = causes protein in milk to thicken
   • Cheese is made from milk that has curdled = lactobacillus bacteria acts upon the curd
   • Quorn mycoprotein single cell protein made by fungus

5. microorganisms to make antibiotics, plants to supply new medicines

   • search for new sources of medicine