B1.1 Keeping healthy

B1.1 Keeping healthy

1. Diet and Exercise

   • A healthy diet consists of:
     • Carbohydrate
       • Release Energy, growth and repair
     • Protien
       • Release energy, growth and repair
     • Fat
       • release energy, growth and repair
     • Vitamins
       • Without these you get defficiency disease
     • Minerals
     • Fibre
     • Water
   • Not a balanced diet = malnourishment
   • Too much energy = gain in weight, too little = loss of weight
     • Warmer country = less food
   • Food supplies muscles energy
   • Metabolic rate
     • Rate of chemical reactions
     • affected by proportion of muscle fat
     • affected by exercise levels
     • genetic

2. Weight Problems

   • Obesity
     • Fat needed to cushion internal organs and as an energy store
     • Too much = overweight/obese
     • Leads to arthritis, type 2 diabetes, high blood pressure and heart disease
     • Early death
   • Losing Weight
     • reduce intake or increase output
     • too much weight loss = malnourishment.
     • Deficiency disease - lack of mineral ions and vitamins
       • common in unbalanced diets

3. Inheritance, Exercise and Health

   • Inheriting Health
     • Metabolic rate
     • Muscle:fat
     • risk of heart disease
     • Blood cholesterol levels
       • Controlling Cholesterol
         • needed for cell membranes and to make vital hormones
         • 2 forms carried by blood - 1 healthy
         • Bad balance, high heart disease risk
         • Balanced diet helps liver balance cholesterol

4. Pathogen And Disease

   • Infectious disease caused by microorganisms (pathogens: eg. Virus/bacteria)
   • Bacteria
     • single celled
     • many harmless
     • useful in food and medical scenarios
   • Viruses
     • Smaller than bacteria
     • regular shape
     • Cause disease in all living organisms (including bacteria)
   • How they cause disease
     • reproduce rapidly
     • Bacteria split in two and produce toxins
     • Viruses take over and destroy the cells
     • Common symptoms
       • headache
       • temperature
       • rashes
       • Bodies response to toxin
   • Ignaz Semmelweis
     • Got doctors to wash hands
     • not accepted
       • too small to see
       • Didn't like the blame

5. Defense Mechanisms

   • Ways Spread
     • Droplet infection
       • coughing / sneezing / talking
     • Direct contact
       • skin
     • Food
       • raw
       • contaminated
     • Break in the skin
       • cut
       • Scratch
       • needle puncture
   • Preventing Entry
     • Skin
       • barrier
     • Blood clots / scabs
     • Mucus in breathing system
       • traps pathogens which are either expelled or swallowed and destroyed in acid
     • White Blood Cells
       • immune system
       • ingest
       • antibodies
       • antitoxins

6. Using Drugs To Treat Disease

   • most drugs do not affect the pathogen, they ease symptoms.
   • Antibiotics
     • Antiseptics and disinfectants kill bacteria outside the body but are too poisonous so would kill you.
     • Work inside the body
     • Damage bacterial cells not your own
     • Do not work on viruses as they are in your own cells
   • Penicillin
     • Alexander Fleming
     • Untidy desk, mistaken experiment
     • Mould stopping bacteria growth
     • Juices from the mould

7. Growing and Investigating Bacteria

   • culture microorganisms to find out more
   • You must give them
     • energy source with minerals
     • warmth
     • Oxygen
     • Nutrients in agar jelly
   • Beware of mutation and contamination from skin, air, water, etc.
   • How to culture them
     • Put in sterilised petri dish with agar jelly
     • Inoculate and incubate (25C)

8. Changing Pathogens

   • If antibiotics are not used correctly, the bacteria develope resistance
     • This is through Natural selection
   • Antibiotics have been overused so developed strains are still around
   • MRSA
     • 1000 deaths a year in UK hospitals
     • Prevented by:
       • Only using Antibiotics when needed
       • Use the correct type of antibiotic
       • Wash hands and dispose of clothing
       • Isolation
       • Cleanliness
   • Mutation and Pandemic
     • New strains spread quickly
     • epidemic (1 country)
     • Pandemic (worldwide)
     • Eg. Swine Flu

9. Immunity

   • All cells have proteins on surface (antigens)
     • White Blood Cells make antibodies to join with antigens and retain memory of the pathogen for future use.
   • Vaccination and Immunisation
     • Vaccine - dead or weakened disease
     • MMR
     • They work for bacterial and viral Pathogens

10. How do we deal with Disease

    • Whooping Cough
      • Thought it led to brain damage, did not
      • Worry caused