1 / 23

C3: Food Matters

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

zev
Télécharger la présentation

C3: Food Matters

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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 wouldn’t 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 that’s 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 haven’t 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 people’s 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.

More Related