Immunity

• 1. Communicable diseases can be passed from one organism to another
• Non communicable diseases can not be passed from one organism to another
• Economic affects of disease are:

  • Unhealthy people cannot work
  • billions of pounds are spent each year by the NHS
  • Money spent on salaries for staff, upkeep of hospitals and drugs/medicine
• cause of communicable disease:

  very small living organisms that can only be seen worth microscope (microorganism)
• There are three types of pathogens

  1. Bacteria
  2. Viruses
  3. Fungi
• Eg of bacteria:

  tuberculosis, salmonella, chlamydia
• Eg of viruses:

  Cold+flu, AIDS, measles, HPV
• Eg of fungi:

  athletes foot, thrush, potato blight
• HIV (AIDS)

  virus spread through exchange of body fluids during sex/infected blood. Prevented by condoms/not sharing needles. Currently controlled by drugs
• Colds+Flus

  Airborne virus (droplet infection) prevented with flu vaccination
• HPV (Human Papilloma Virus)

  Virus spread through sexual contact. Vaccination offered for 12-13 year old girls to protect against cervical cancer.
• Salmonella

  Virus spread through contaminated food. Cook food thoroughly and don’t mix cooked+uncooked foods to prevent spread. Treated with antibiotics
• Tuberculosis

  Airborne Bacteria prevented with BCG vaccination and treated with antibiotics
• Chlamydia

  Bacteria spread through sexual contact. Prevented by using a condom and treated with antibiotics
• Athletes foot

  fungus spread through contact. Avoid direct contact in areas where spores are to prevent
• Potato blight

  Fungus, spores spread in air from plant to plant. Prevented with crop rotation and fungicide
• Body defence: Skin

  Excellent barrier to micro organisms
• Body defence: Mucous membranes

  openings of body (nose/respiratory)protected by mucous membranes which trap micro organisms and prevent them going any further
• Body defence: Blood clotting

  prevents more blood escaping acting as a barrier against infection
• Antigens

  chemicals on the surface of invading microorganisms that the body recognises as foreign
• Antibodies

  Produced by lymphocytes

  Join with antigens and form a clump of microbes
• Antibodies have a complimentary shape to antigens of the microbes
• Phagocytes

  Move around in blood and destroy microorganisms trapped by antibodies
• Phagocytosis

  Phagocytes surround engulf digest and destroy
• primary responses

  antibodies produced slowly and at at low numbers
• Secondary response

  with re infection, antibodies produced quickly and at a higher level due to memory lymphoctyes
• Immunity

  When antibody levels are high enough to combat microorganisms
• Active immunity

  Body produces slow acting and long lasting antibodies
• Passive Immunity

  Fast acting and short lasting Ready made antibodies injected into body when rapid protection required
• Vaccinations

  dead/modified pathogens injected into the body causing the body to produce antibodies at a high enough level to prevent person becoming ill in the future as memory lymphocytes are produced
• Booster vaccination

  needed if first vaccination doesn’t provide enough antibodies for immunity
• Vaccinations are a form of active immunity
• Structural plant defence mechanisms

  Waxy cuticles prevent entry of microorganisms and thick cell walls surround cells
• Chemical plant defence mechanisms

  produce chemicals harmful to infectious microorganisms (antimicrobial)
• Penicillin

  antibiotic produced by fungi which kills/prevents growth of bacteria

  discovered in 1928 by alexander fleming
• Florey and chain

  isolated a purer form of penicillin and began large scale production
• Making penicillin

  Made in carefully controlled conditions

  Grown in large biodigesters/fermenters

  Downstreaming required
• Optimum conditions for penicillin

  24°C with good O2 supply and slightly alkaline pH
• Downstreaming

  Extraction, Purification+packaging
• Making new medicines

  preclinical trials before drug used on people and clinical trials testing on people