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C3: Food Matters

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C3: Food Matters Many Chemicals in Living Things are Natural Polymers Carbohydrates: Carbon, Hydrogen, Oxygen Cellulose, Starch, Sugar Proteins: Carbon, Hydrogen ... – PowerPoint PPT presentation

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Title: C3: Food Matters


1
C3 Food Matters
2
Many Chemicals in Living Things are Natural
Polymers
  • Carbohydrates
  • Carbon, Hydrogen, Oxygen
  • Cellulose, Starch, Sugar
  • Proteins
  • Carbon, Hydrogen, Oxygen, Nitrogen
  • Amino Acids, Proteins

3
  • There is continual cycling of elements through
    consumption of living organisms and decay

4
Crop Harvesting
  • Elements such as nitrogen, potassium and
    phosphorus, are lost from the soil so that the
    land becomes less fertile unless these elements
    are replaced

5
Intensive Farming
  • Try to produce as much food from their land as
    possible (Maximise Yield)
  • Synthetic Fertilizers replace soil nutrients
  • Pesticides/Fungicides kill pests and
    disease-causing fungi
  • Herbicides kill weeds that compete with crops
    for nutrients, light, and water

6
Organic Farming
  • Take care to produce food without damaging
    environment. Follow UK Standards.
  • Manure replace soil nutrients
  • Natural Predators control pests
  • Crop Rotation replace soil nutrients naturally
    reduce crop diseases

7
Food Additives
  • Colours More attractive
  • Flavourings Enhance taste
  • Artificial Sweeteners Reduce amount of sugar
  • Emulsifiers and Stabilisers Help mix ingredients
    together that wouldnt normally mix. EG oil and
    water
  • Preservatives Keep food safer longer. Prevents
    growth of microorganisms
  • Antioxidants added to foods containing fats or
    oils to prevent them deteriorating by reaction
    with oxygen in the air
  • Scientific Advisory Committees carries out risk
    assessments to determine the safe levels of
    chemicals in food

8
E Numbers
  • Additives with an E number have passed a safety
    test and been approved for use in the UK and the
    rest of the EU
  • Health concerns about the use of some additives

9
Natural Toxins
  • Natural chemicals in plants may be toxic, cause
    harm if not cooked properly, or may give rise to
    allergies in some people

10
Alfatoxin
  • A harmful chemical in food, produced by moulds
    that contaminate crops during storage

11
Harmful Chemicals
  • Traces of pesticides and herbicides may remain in
    the products we eat
  • Harmful chemicals may form during food processing
    and cooking
  • Foods rich in starch thats been cooked at high
    temperatures contain acrylamide. This is known to
    cause cancer in animals

12
How to Reduce how many Harmful chemicals you
consume?
  • Eat more organic foods
  • Eat foods which havent been processed very much.
    Ie fresh fruit and vegetables.

13
Food Labels
  • Give information about ingredients, additives,
    nutrients.
  • Can be misleading. It might say fat free, but
    how much sugar is in it?

14
Food Standards Agency (FSA)
  • Food Standards Agency is an independent food
    safety watchdog set up by an Act of Parliament to
    protect the public's health and consumer
    interests in relation to food

15
Regulations and the Future
  • Scientific research and applications are subject
    to official regulations and laws (government)
  • Technically feasible what can be done
  • Values what should be done
  • Sustainable development aims to meet human needs
    while preserving the environment so that these
    needs can be met not only in the present, but
    also for future generations

16
Precautionary Principle
  • It is impossible for anything to be completely
    safe. A positive change to the environment for
    one organism (adding fertilizer) may be a
    negative one for another.
  • Better Safe than Sorry
  • To the people who believe a new technology is not
    safe, it is up to them to prove that it is.
    Otherwise society / individual will continue to
    believe that there is a danger.
  • Examples
  • A new untested pesticide

17
Digestion of Protein
  • Protein broken down into Amino Acids and then
    transported by the blood around the body.

18
Digestion of Starch
  • Starch broken down into Glucose and then
    transported by the blood around the body.

19
Protein
  • Cells grow by building up amino acids from the
    blood into new proteins
  • These consist mainly of protein
  • haemoglobin in blood
  • tendons
  • muscle
  • skin
  • hair

20
Excreting Protein
  • Excess amino acids are broken down in the liver
    to form urea, which is excreted by the kidneys in
    urine

21
Blood Sugar Levels
  • High levels of sugar (common in some processed
    foods) are quickly absorbed into the blood
    stream, causing a rapid rise in the blood sugar
    level
  • The Hormone Insulin controls Blood Sugar Levels

22
  • Type 1
  • Starts in childhood
  • Pancreas stops producing enough insulin
  • Controlled by insulin injections
  • Type 2
  • Usually starts in adulthood
  • Risk factors obesity, poor diet
  • Body no longer responds to its own insulin or
    does not make enough insulin
  • controlled by diet and exercise

23
Benefits and Risks
  • Can suggest benefits to a known risk and offer
    reasons for peoples willingness/reluctance to
    accept the risk of a given activity
  • Convenience foods are easy and quick for people
    to use. Eg 5 minute microwave meals. Although
    they may have undergone lots of processing.
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