C3: Food Matters

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C3 Food Matters
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Many Chemicals in Living Things are Natural
Polymers

• Carbohydrates
• Carbon, Hydrogen, Oxygen
• Cellulose, Starch, Sugar
• Proteins
• Carbon, Hydrogen, Oxygen, Nitrogen
• Amino Acids, Proteins

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

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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

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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

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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

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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

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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

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Natural Toxins

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

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Alfatoxin

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

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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

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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.

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Food Labels

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

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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

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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

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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

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Digestion of Protein

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

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Digestion of Starch

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

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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

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Excreting Protein

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

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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

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• 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

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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.